The bottom-line of our comets don't cause CMEs argument is that the SOHO comets never reach the solar surface, they're inconsequentially tiny compared to the Sun...
So it boils down to who are you going to believe? Them or your lying eyes? LOL
The overwhelming evidence, based on many actual recorded collisions, is that they do - even if the scientists don't understand what causes it. Bet they so work on the side as global warming consultants as well. lol