If you thought you were behind after he called your flop bet in hand 2, why bet the turn? If you were trying to get him out, more of a bet is needed. If you were waiting for aggression from him and planning to fold afterward, why not just check? As small a bet as you made (relative to the pot/flop bet), I could see decent players making a move even with nothing. On the other hand if you'd put him all-in when the 8 came, he may well have folded, unless he held the 8.