If a butterfly on one side of the world flaps his wing, would it cause tidal waves on the other side?

It's a chaotic result of the event. There's a trillion possible outcomes, and one of the trillion would be that the molecules of the atmosphere are alligned just right that the flapping of the butterfly wings makes the difference between a tidal wave occuring and not occuring. Like the straw that broke the camels back, it's not really responsible for the outcome but it's the event that induces the outcome.

Yes... if its Mothra.

Seriously, you could envision a process where the flapping disturbance propagated to affect the weather, affecting rainfall over a geologically sensitive area, affecting stresses along fault lines or potential land slides, etc.