So how did 2 1/2 Men run a rerun of an epiosde about an earthquake last night?

The episode show in NYC last night at 7:30 on WPIX Channel 11:

Zejdz Zmoich Wlosow (Get Off My Hair)
When Judith s pipes burst after an earthquake, Alan invites her to stay with him at Charlie’s house.

Was this coincidence or can the station substitute another episode? I know the Simpsons aired the episode with the “Get Smart” parody opening sequence when Don Adams died.

I have no idea… but I think they MUST be able to pull certain episodes from the syndicated episodes a station has at any time.
Too often a Simpsons re-run will come on from years ago and have an oddly topical reference or plot.
Or a few years ago I remember Dakota Fanning had a movie come out and I swear the one episode of Malcolm in the Middle that she was in was played several times in a short period of time–like there was NO way it came back up in rotation that quickly. Or when Heroes was popular, Hayden Paniterre’s episodes got replayed a lot.

Sure it might be coincidence…

The companies that own the syndication rights, or whatever the relevant rights are, can play whatever episode they want as long as they own it. I’m sure they are willing to alter their schedules once in a while if they think they’ll keep more viewers by being topical.

For some reason I was watching syndicated Malcolm all the time at that time and those episodes actually came up in rotation naturally.