On the turn I expected him to continue with more random Ks and Js than you did. Also one thing you haven't considered is the equity I gain when he folds ANY hand with one club in it on the turn, so even if he's folding his QcJ, J10c hands I gain equity by betting + I obv gain value if they call aswell. Still, it seems like the value was pretty thin if there at all and I'll certainly look more into not value betting this kind of spot so thinly in future.

Disagree with you about the river though. Bad players love to see showdowns and I pretty much never see random 5nl players make thin value bets in position on the river, whether they know that's what it is or not. Pretty sure when he makes that river bet my equity vs his range falls from somewhere close to 50% to about 5%.