Peso v. Hollaway, 2012 BCSC 1763 is another case where there is a discontinuity between the trial judge’s statement of the law and the trial judge’s conclusion. The result seems to be supportable on the evidence set out by the trial judge. The decision, ultimately, is based on the judge preferring the plaintiff’s evidence over the defendant’s.
P alleged he was injured in a motor vehicle accident. H was found at fault. The trial judge summarized his conclusions.
 The Third Party Insurance Corporation of British Columbia’s position is that Mr. Peso was suffering significant symptoms shortly before the collision. It submits that what occurred following the collision was a minor aggravation of a continuous disease process which was already progressing. This argument is based on the pre-collision reference in the clinical records to his back pain as being severe. The Third Party says this is a “crumbling skull” case; The Plaintiff says this is a “thin skull” case of tolerable episodic pain exacerbated by the collision into one of chronic pain.
 Which scenario is more likely? I have concluded that it is the latter. I have had the benefit of extensive written submissions provided by Counsel. I prefer plaintiff counsel’s analysis and adopt much of it as apposite to my following reasons.
After reviewing the evidence the trial judge set out the law. Each sentence in each of the next two paragraphs is an accurate statement of law (for British Columbia).
 The Plaintiff must establish on a balance of probabilities that but for the Defendant’s negligence, the Plaintiff would not have sustained the injuries and losses claimed. The test is to be applied robustly, and with common sense. Clements v. Clements, 2012 SCC 32. There may be more than one cause of an injury. Causation is established if the contribution of the Defendant’s negligence was more than de minimis: Athey v. Leonati 1996 CanLII 183 (S.C.C.) at paragraph 44.
 Where the injury caused by the Defendant is indivisible from the injuries arising from other causes the Defendant is responsible for the whole of the Plaintiff’s loss: E.D.G. v. Hammer, 2003 SCC 52 (CanLII), Ashcroft v. Dhaliwal, 2008 BCCA 352, Bradley v. Groves , 2010 BCCA 361 (CanLII).
Now imagine each sentence is a piece of a jigsaw puzzle. When the pieces are put together, does the picture make sense? The trial judge’s conclusion on causation – in fact and law – is the next paragraph.
 Mr. Peso had a condition known as adolescent disc disease. The natural history of this condition would have caused Mr. Peso episodic back pain but little in the way of disability. But for the collision, Mr. Peso would not have undergone surgery and would not have been left with a back permanently vulnerable to flare ups, deterioration, and further surgery. Thus the injuries sustained in the collision are indivisible from those that existed before the collision. Dr. Street opines that the collision significantly aggravated Mr. Peso’s condition and made it permanently worse. Dr. Werry agrees with this characterization of causation in his report dated February 14, 2008 and he affirmed this at trial. Accordingly I am satisfied the Defendant is responsible for the whole of Mr. Peso’s loss.
Let’s parse . I’m going to put the sentences (in order) in groups.
A. Mr. Peso had a condition known as adolescent disc disease. The natural history of this condition would have caused Mr. Peso episodic back pain but little in the way of disability.
B. But for the collision, Mr. Peso would not have undergone surgery and would not have been left with a back permanently vulnerable to flare ups, deterioration, and further surgery.
C. Thus the injuries sustained in the collision are indivisible from those that existed before the collision.
D. Dr. Street opines that the collision significantly aggravated Mr. Peso’s condition and made it permanently worse. Dr. Werry agrees with this characterization of causation in his report dated February 14, 2008 and he affirmed this at trial.
E. Accordingly I am satisfied the Defendant is responsible for the whole of Mr. Peso’s loss.
A, B, & D together, mean that if the accident had not occurred then the significant problems that P had after the accident probably would not have occurred. They mean that the accident, superimposed on P’s prior condition, produced significant, compensable, problems that P probably would not otherwise have had. Put that way, that’s a standard but-for finding supporting the trial judge’s assessment of damages.
That’s Athey, of course, para. 41.2
If it was necessary to have both the accidents and the pre-existing back condition for the herniation to occur, then causation is proven, since the herniation would not have occurred but for the accidents. Even if the accidents played a minor role, the defendant would be fully liable because the accidents were still a necessary contributing cause.
[Emphasis in original.] But the trial judge didn’t stop there. He wrote what I’ve called proposition C: ” Thus the injuries sustained in the collision are indivisible from those that existed before the collision.” Given para. 68, we can’t take proposition as nothing more than a restatement of A, B & D triggering applying Athey: that the pre-accident condition and the accident were cumulatively necessary.
We have to understand the trial judge to have used “invisible injury” in proposition “C” in the meaning given that phrase by BC law. Bradley v Groves at  has the definition of indivisible injury for British Columbia: “Divisible injuries are those capable of being separated out and having their damages assessed independently. Indivisible injuries are those that cannot be separated or have liability attributed to the constituent causes.”
If so, then C amounts to a statement that P’s condition before the injury was just as capable of being a cause of P’s post accident condition as the accident even if the accident had not occurred. If that’s what the trial judge meant, then he should not have awarded the plaintiff anything for those conditions because there was no change in the plaintiff’s original position. That’s clear from Athey at  and [41.1]
 … The essential purpose and most basic principle of tort law is that the plaintiff must be placed in the position he or she would have been in absent the defendant’s negligence (the “original position”). However, the plaintiff is not to be placed in a position better than his or her original one. It is therefore necessary not only to determine the plaintiff’s position after the tort but also to assess what the “original position” would have been. It is the difference between these positions, the “original position” and the“injured position”, which is the plaintiff’s loss. In the cases referred to above, the intervening event was unrelated to the tort and therefore affected the plaintiff’s “original position”. The net loss was therefore not as great as it might have otherwise seemed, so damages were reduced to reflect this.
[Emphasis in original]
[41.1] If the disc herniation would likely have occurred at the same time, without the injuries sustained in the accident, then causation is not proven
The indivisible injury argument, for what it’s worth, was created to avoid the problem of multiple tortious causes (with or without innocent causes) where the evidence does not permit the court to say, on the balance of probability, that the all of the tortious causes (and the innocent causes, if any) are cumulatively necessary. That wasn’t the problem in Peso.
The trial judge’s review of the evidence in - and the summary paras. [6-7], taken at face value, shows that the judge did not mean to say that the pre-accident condition was also a sufficient cause of P’s significant post accident problems. He specifically rejected the defence expert on that point – see -. But that’s literally what the trial judge wrote by referring to the indivisible injury concept in “C”.
By the way, the trial judge didn’t explain what robust, pragmatic, with common sense means. The trial judge also didn’t explain why he wasn’t applying the BC rule that the Snell robust, common sense approach to but-for can’t be used where expert evidence is called on causation, most recently affirmed (for BC) by the BCCA in Ediger v. Johnston, 2011 BCCA 253 at -, leave to appeal granted 2012 CanLII 8362 (SCC)
 This court confirmed in Moore v. Castlegar & District Hospital (1998), 49 B.C.L.R. (3d) 100 (C.A.) that “where both parties have led expert evidence on the issues of causation, it is not open to this court to apply the ‘common sense’ reasoning urged in Snell” (para. 11).
The Ediger appeal is to be argued on December 4, 2012. The SCC might have something to say about the BC rule.