A few points, Matthewc.
In general, if you were right I'd agree with you!
But I can't – at least not until there is more evidence on the table.
The issue (for those who haven't been following this closely) is this. When a PR is abroad with his/her Canadian spouse, can he/she count those days toward the 730-day quota? The Law states that the PR can count those days if he/she accompanies the Canadian spouse. But what constitutes “accompany”? Does it mean the spouse must have the primary reason for being abroad, and the PR is abroad because of the spouse? Or can “accompany “simply mean that as long as the two are together, abroad, the PR can count those days?
Mathewc believes the latter; I believe the former. Here come the specific points.
1) First, this is a rather subtle legal issue, and professional lawyers have found it necessary to go to court to settle their differing interpretations of the Law. So everyone reading this should take our arguments with a grain of salt.
For every court case, there was a border officer who challenged the PR, an Immigration Officer who concluded that the PR had not met the 730-day quota, and an appeal(court case). My preliminary advice is to try to avoid this morass of challenge, proof, appeal, time delay, and cost -- if at all possible. That is to say, try to avoid relying on the “accompany” clause if one can; spend 730 days in Canada.
2) Second, Mathewc, you say you haven't found the court case that PMM referred to. Until you do, you aren't on solid ground to judge the matter validly, and to accept or dismiss another's view is premature. You may be correct, on further analysis, but not on the evidence presented so far.
3) Third, there is a danger to advising a relaxed interpretation of the “accompany” exception to the 730-day quota. You might (inadvertently) encourage PRs to rely on your liberal (and so far unproven) interpretation. If your view is wrong, they might find themselves in default of the 730-day quota, and out of luck.
But enough of the cautions and caveats. Let's do play “amateur lawyer” and look at the cases. You're right that many don't turn exclusively on the meaning of “accompany”; other considerations are included in the judgments -- which confuses the issue for us.
Nevertheless, I found the following case which focuses closely on the issue of “accompany”, and I present some relevant abstracts here. I have underlined and italicized the salient parts, but I hope you'll go to the case itself, and test my interpretation.
Smith v. Canada (Citizenship and Immigration), 2007 CanLII 67256 (I.R.B.)
 The appellant was born in Germany on November 21, 1959, and is a citizen of that country. She became a permanent resident of Canada on June 9, 1967, when she was landed as a seven-year-old accompanying her parents. She remained in Canada for less than three years and then moved to the United States, at the age of ten, with her parents, when her father was transferred by the company he worked for from Mississauga, Ontario, to the Cleveland area in Ohio.
7] In April 1991, the appellant met David Strickland, a citizen of Canada, born in St. John's, Newfoundland. He worked as a long-distance truck driver. By 1993/1994, their relationship became more serious. They began to see one another more frequently. The appellant gave him a key to her house; he stopped smoking at her urging and they put the money saved into a joint bank account for taking holidays together; and he assumed a parental role in raising the appellant's daughter, Ashley.
 Both the appellant and Mr. Strickland testified that he spent about 70 per cent of his time in the United States between living with the appellant and being on the road. The other 30 per cent of his time he spent in Canada, where he maintained a residence. Mr. Strickland organized his life to spend as much time as possible with the appellant in the United States. From 1996 to 2006 he lived between Ohio and Ontario spending the majority of his time in the United States. Throughout this time period, Mr. Strickland also maintained a residence in Ajax, Ontario. He had his office there and lived there when he was in Canada. The appellant visited him in Canada about one weekend per month.
7] The appellant contested the immigration officer's determination that she had not complied with the residency obligation under section 28 of IRPA in both law and equity.
 The panel concludes that the immigration officer's determination is valid in law
. However, the panel finds that, taking into account the best interests of a child directly affected by this decision, there are sufficient humanitarian and compassionate considerations to warrant special relief in all the circumstances of this case. The appeal is allowed. [Note that in Law she had not met the quota, despite her claim that she was accompanying her Canadian husband. Her appeal was granted on other grounds.]
 Where the panel does not accept counsel's argument is around the phrase “outside Canada accompanying a Canadian citizen”.
Subparagraph 28(2)(a)(ii) requires that a permanent resident accompany a Canadian citizen outside Canada. The panel is of the view that the common-law relationship in this case involved a Canadian citizen accompanying a permanent resident outside Canada, not vice versa.
30] When the appellant and Mr. Strickland became romantically involved, it was Mr. Strickland, the Canadian citizen, who chose to alter the pattern of his life to spend as much time as possible in the United States with the appellant, the permanent resident.
 In the panel's estimation, Mr. Strickland accompanied the appellant. The appellant did not accompany Mr. Strickland as envisaged by subparagraph 28(2)(a)(ii). They were in one another's company, but, that in the panel's opinion that is a different concept from the appellant accompanying Mr. Strickland in the United States. [Note: this is as close to the nub of the issue as we can come, and I think this at least casts serious doubt on any assurance that the two (PR and Canadian ) need only be together abroad for the days to count toward the quota.]
 The panel would draw the analogy of the concept of an accompanying or non-accompanying dependent. Accompanying means to go with.
 This is further confirmed by the primary definition of “accompanying” in both the Concise Oxford Dictionary, which includes “go with”, and the Gage Canadian Dictionary which includes “go along with”.
 The panel is satisfied that the appellant did not go with or accompany David Strickland to the United States. Consequently, she is not a permanent resident of Canada on the basis that she has been outside Canada accompanying a Canadian citizen who is her common-law partner as intended by subparagraph 28(2)(a)(ii) of IRPA.
 In the panel's view, the scheme of IRPA, in a fact situation such as this case presents, suggests that a Canadian citizen, in a legitimate common-law relationship with a Green Card holder in the United States, should sponsor that person to Canada and not rely on subparagraph 28(2)(a)(ii).