brady knew the balls were flat, he admitted in 2011 he had a preference, and he surely noticed it in the game.
brady actively participated in a coverup, and lied about knowing the Deflator, despite them having some long convo and lots of texts.
We can use the wording of the report 'probable', etc... but all know brady knew the balls were flatter, and he lied to the NFL about knowing the Deflator. That's why he is suspended. He lied to the commissioner/investigator and embarrassed the NFL. He's luck it's only 4 games to be honest.