I don't have a great understanding of relativity, but doesn't general relativity state that things happen relative to the observer's frame of reference. So, in fact, this event did occur either 2 weeks or 4 billion years ago, or anywhere in between, depending on where you're standing?
The only answer you've gotten so far is garbled nonsense ... and I don't want to make similar mistakes. So I'll stay very simple:
1. You don't need general relativity to talk about this. Special relativity (that's special as in "special case") suffices.
2. It's true that in general, you can't talk sense about the idea that two events happened at the same time; in this case, say, that you looking at your watch two weeks ago and the explosion "really" happening were simultaneous.
Relativity is about the perceived passage of time as observed in reference frames traveling at different velocities relative to one another. So it would have happened two weeks ago to someone traveling very (very) fast, but that's got nothing to do with how far they are from the event itself (i.e. where they're standing).
The frame of reference here is not one of location but of relative velocity. You are allowed to account for the distance the light had to travel before it reached you (and you observed the event) in Relativity, just as in anything else as far as I'm aware.
Can anybody clarify or correct me?