Well, with so few hands, you have to adjust his stats.
He played his 2nd now, thus so far he played 6/3
You know little to nothing about his postflop play, so don't let tightness preflop scare you postflop. Players at this limit who play very, very few hands often can't let go of their hands once they start putting money in (very profitable exploit in their playing style). He appeared to have won his previous hand though and he did play some before (else he would have had a maximum of 100 $) so that's another reason to relativize that 3/3 statistic)
I wouldn't consider it a mistake to fold here this time around, however, this is very exploitable. Again, his preflop play says nothing about his postflop play.
The possible flushes he might have is AK, AQ and KQ, with AK being dismissable as he didn't raise preflop (normally AQs and KQs are a reraise too, but you never know). His postflop play of calling the flop and raising the turn is indicative of a flush, however, it's just as often a float or a bad move by a tight player who's got his set of 6, 9, T or J and didn't want to scare you away on the flop and now was cursing because a flush might have hit (he didn't see the straight), and tries something called delayed protection. Personally, I would have gone with it...
Being doublestacked it's a bit tougher, but still ... however, with only 10 $ invested, a fold isn't wrong either. Perhaps even better ... we'll never know I suppose 
dealt to Hero (CO)
