I think they were so focused on established strategies, that they weren't thinking like someone who doesn't know them. It's like being a high ranked player in CS with a bunch of low rank people. You're doing stuff typical of high level play, and they aren't so it throws you off. Like, someone being in a position that is commonly thought to be a bad play can suddenly become good again if your opponent is treating it as being empty all the time and you catch them off-guard.