Some baffling responses to this one, and I feel a bit sorry of the OP who's being treated as a naughty - or at least foolish - schoolboy by some.
The other guy was 100% in the wrong. It has always been the case that if you stray on to another fairway you wait until those playing that hole have either played first or invited you to play before them if they so desire. In the absence of any such an invite you wait until they have played and gone.
What the OP 'should have, could have' done is almost irrelevant as the other guy was completely in the wrong.
