"Do you think this was a good situation to go for a river checkraise against a smaller flush?"


No!


"Or, with a paired board, is it reasonable to be suspect of a bigger full-house?"


Either a bigger full house or a missed full house. Your friend has to decide if his opponent would call a river bet with a flush, or a straight, 3-3-X-X, 5-X-X-X or A-A-X-X or not.


I think I would have tended to bet the hand on the river. Why? The river was a three. There is hardly any way the three could have helped your friend's opponent more than it helped your friend. If your friend's opponent had a higher full house, he/she probably would have raised on the turn. The call on the turn looks most like 5-X-X-X, hoping to make a full house on the river (but could logically be some other hands as well).


Just my opinion.


Buzz