Did I just miss a lot of value here?

Based on my recent experience milking donkeys...wait a second, nevermind. Anyway, I'd say at least the last 5 times a donk has had a monster against me, he's checked the river. Almost every time has been a flush and I've checked behind b/c I never really had enough to value bet anyway. So I guess I agree that bad players scare me more with a river check than a solid player.