How criminal investigations work
1. You don't need strong rock solid proof to investigate, you need reasonable belief that something illegal happened.
2. You investigate
3. If you find evidence to prosecute a crime you charge if not you dont
4. Conviction process
We're in step 2. Just saying no collusion a bunch of times doesn't change that. Proof will come out in step 4 if we get there.
Lol, with the way the Mueller teams leaks? If there was a shred of evidence we would know about it.