And we see them punching each other plenty of times without waves to the point of a character even asking why there aren't anymore waves, all while Goku is still in God mode.
Also, it also happens when their energy blasts meet so that doesn't work either.
Your explanation isn't.
Edit: Hell, the actual narration notes SSJ Goku and Beerus are punching each other with universal level power which is in keeping with every other statement we had in the fight.
Edit 2: And it's not like SSJ Goku post ritual doesn't have God Ki so that's another problem with your theory.