I wouldn't expect him to continue with his bluffs by betting 1/2 pot on a blank turn, so this would be for value in his mind. At that point i'd love to have seen him play a bit beforehand to get a read on his betsizing.
Does he get the idea of pot odds ? Probably not, he minraised the flop.
Is 13$ a big bet from his point of view ? No clue.
In other words, does he know he's pot-committing himself when he bets that, and would he bet more if he had more than a top pair ?
Without knowing anything, this is pretty marginal and high variance. If you feel like folding to save yourself a headache, no argument here.
I would probably assume that a 1/2 pot bet on a blank turn is a lot less aggressive than his c/r line on the flop, and put him on a J with or without a redraw, which i don't think he's folding anymore.
Since i'm not folding anymore either when i call, i would just shove over right there, as there are a lot of river cards i don't want to see.
I'd like to get a judge's opinion tough.