I really have no problem CCing here against an unknown. He could be getting stupid on you with AQ or KQ, or trying to make a play on you with an openended straight draw or some other strange hand. You said he in a NL player. That leads me to believe he could be a big fat
I'm not really afraid of seat 4 having a J. I think it's more likely he has a Q tbh. Strangely enough, a lot of horrible loose players will fold their mid-pairs when it comes one more back to them on the turn, even when it may even be correct for them to draw because of the pot size and the situation. It's one of the few situations where these people have an opportunity to make "smart" laydowns, and it makes them feel good inside methinks.
The exception is when they are royally stuck.