[4_2_it]

Hard to say it was an angle shoot since you had no way of knowing the guy would string bet. You asked for a ruling and played your hand. Kudos to you.

The only scenario where I think you could be criticised is as follows (again, I don't think this is the case based upon your OP):

Suppose string-better was doing this all night and you (Mr Angle Shooter) were waiting for an opportunity to trap him and other fish with AA. Then I would say you are similar to the guy who observes an opponent placing his cards behind his chips (never says a word for 3 hours) and then waits until he gets AA to declare that his opponent is all-in because his chips are in front of his cards.