I think I know what happened. Like Halgroda just said--we stated when Episode 1 came out that our hope was to have Episodes release 1-3 months apart. Episode 3 released in February, so probably May came from someone estimating the 3 months out from that point. Whoever may have said it, though, there's never been an official date, vague or otherwise.
No problem, and welcome to the boards, btw

*goes to edit wikipedia so others don't get too confused...*