Have you seen the content of the security update? It doesn't really excuse the 4 days between iOS and OS X updates, but it's a hell of a lot more than FaceTime updates.
While this is too long IMO, Similarly critical bugs in windows have been left unfixed for years.
While that may have been true, I dare say that the burnt child that is today's Microsoft would not have mishandled this so horribly.
10.9.2 has been in beta for weeks and was evidently just about to be released. It made a lot of sense from a QA perspective to do it just the way they did.
I'm fully on board with the "bugs happen" point of view, but if they really have had this particular fix in the pipeline for weeks, then no, they really really should have done an out of band update of a much smaller scope.