You may have 4 outs to a split. I wouldn't rely on those as 4 clean outs; the bettor having a T is not out of the question.

I do agree with the bet/fold line on the river. If he has a straight or has made two pair, which I would think is the most probable hand for him on the turn, he will almost definitely come over the top on the river. At this point you can fold.

Edit: This is assuming that the ace hasn't fallen on the river. I may be tempted to call the raise on the river; a T isn't out of the question, I think a good percentage of the time he has a lesser two pair.