It’s impossible to be certain, since we don’t know the detailed mechanisms of two pieces of magic that are involved (each of which is highly non-trivial on its own).
My guess was that Voldemort would still be able to leave his body as long as the Process of the Timeless has not quite snapped into place (which did not happened until a few moments after Harry lost the cloak.) Leaving his current body voluntarily might take some time, if the descriptions of the Sphere-of-Stars-spell is any indication, so he might not be able to finish that process in time. (Killing his body, on the other hand, would presumably expel his spirit instantly, so he could escape in that manner.)
(… all of which is, of course, just a fancy way of shrugging my shoulders and saying “I dunno” ;) )
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 110.
There is a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: