I think it's impossible for it not to be poorly implemented because the gesture is inherently ambiguous (or becomes so when you overload it).

I think what "poorly implemented" actually means for touch screen gestures is to be lacking the customizability to reassign or disable infuriating behaviors.

Gesture configurability is nonnegotiable: when implementing gestures, have the configuration system in place first and make sure every single behavior is tied to a preference.