Which is the correct thing to do. An immediate accident would be if a car was reversing out of a blind drive way, and another was approaching, and you're seeing the whole thing about to happen, but it isn't clear either of the two other drivers are. That's when you honk.

If you can mitigate an accident by simply stopping, then don't honk. It's generally only for things you can see is about to happen, that the others probably haven't seen, or is aware of. Whether or not the accident will involve yourself is secondary.