Turns out it was a pretty good idea. No chest pain, but EKG showed a MI and iStat troponin came back hugely positive. Rushed up to the cath lab and ended up doing pretty well.
There are plenty of BS complaints in the ED, and plenty of people who feel sheepish coming to the emergency room for what turns out to be a negative work-up. I wish there was a simple way to predict in advance what's emergent and what isn't, but cases like these prove that it really is better to be safe than sorry.