I would probably put it in on the turn half the time and call/check-call the river the other half, but that may not be the best idea. You said in your OP that the turn was his most aggressive street, so he could be making a play here.

Have you seen him play any hands, or has PT done all of the observing for you? Has he used a similar line before, and if so what did he have?

How does he play sets/2pr. QJ is a definite possibility here. People love QJ and play it far too often.