I have in fact written two further pieces on the 2008 prorogation, in which I enlarge on a number of issues. My conclusion ends up being the same, but I think my appreciation of the nuances and the appreciation that there really is a considerable foundation for the opposing arguments.... And this is one of the perks of being an academic: one can say that the other position is brilliant, but I just happen to like mine a little more or find it a little more convincing.
In terms of the 2008 prorogation, very clearly, there are strong arguments to be made that the Governor General should have acted on the advice. The normal position is that so long as the government has a relatively fresh confidence mandate from the House of Commons, it can insist on most matters put to the Governor General. The exception to that in this case was, I felt, that it was unconstitutional advice in trying to prorogue the House while a clear confidence motion was on the agenda and would be held within a matter of days. That's where I had problems with it.