The bottom line is that the complexity of the issue makes it open to debate and interpretation.
here we have a situation were a captain of an aircraft has been seriously injured in flight, injured to the point that he has to subsequently spend two weeks in hospital. Now all you aviation lawyers will know that at the point of injury his licence was suspended so he is hardly the commander anymore and thats even before considering half of his body is hanging out of the DV window? If ever you wanted a test case to prove that a pilot who set off as a first officer without signing the tech log but landed as the commander this is it.
Perhaps if it happens again the FO will say, well i cant be the commander because I didnt start out before flight as the commader so i will just pop down the back while the cabin crew hang on to him.
I would say the wise would view this one as a 'test case' all though of course I suppose if it disproves your argument you would prefer
It doesn't make your surmise correct though,