The culprit? Lack of climate control. This was in un air conditioned basement apartment, the outside temp reached 95+ for at least four days running.
10 bottles out of 44 survived. 4 of those went to Canada with me (where I was when this happened).
On the upside, I cracked open the first of the remaining bottles this evening, with my landlord (who has been understanding). Its pretty good if I do say so myself. Hes not much of a stout fan, but still enjoyed it.