Sam, this was not a very specific statement. If it was said about a particular individual, you might have a point, because we can never know when a particular gezeirah is sealed. (Although at times, HKB’H might reveal something specific to a tzaddik, so it’s not out of the realm of possibility.)
It is certainly not beyond R’ Vosner, though, to be able to make the connection between a certain type of puroniyus and a certain aveirah.