Never allow your eyes to catch too much fancy on anything that looks promising... Truth is, the casinos wouldn't allow an obvious route to cheat, maneuver or win against their edge open to you. If you can possibly spot the loophole, and it doesn't look really odd, then it's a trappppp!!!! Run!

In a case like the one described in the OP, I think nobody would be in their best behavior - it's not even about how much you wagered... It's about having the thick green mark on 9 games outta 10, but the last one that obviously holds you begins to waver.