So what you are saying is players are assumed guilty until proven innocent?
The case was tried in two different states and dismissed due to lack of credibility of the witness; in other words, the witness was clearly hoping for a pay day. Then the NFL took over the investigation and tasked Kia Roberts with the job of interviewing both parties, Zeke and Tiffany. After several meetings with both, she came to the same conclusions as the courts, siting that the accuser is not credible and that the NFL should not suspend Zeke. The NFL ignored her findings, deciding that despite Tiffany already being caught in several lies, such as a text to a girlfriend requesting she lie on her behalf about Zeke abusing her and even considered extorting money out of Zeke by threatening to release a sex tape, that there was enough evidence to move forward with a suspension.
Whether or not their is a Cowobys bias is questionable; I'm with you there. But considering how the NFL botched Ray Rice, Josh Brown, and Greg Hardy's DV cases, they did need a high profile case to attempt to right their previous wrongs. It's clear the NFL started with a verdict of guilty and then worked their way back to prove it, dismissing any evidence that would suggest otherwise.
He may still be suspended in the end simply because as you pointed out, the NFLPA gave the commish the power to do so. But that doesn't in any way mean that Zeke is guilty. In fact, I'd say I'm fairly confident he's innocent for one very important reason: Before this became an investigation Zeke could have made this go away by simply paying Tiffany what she wanted, which was reportedly enough money to go on a vacation and get a boob job (direct quote from Tiffany's text, btw). But he didn't He maintained his innocence. I'm not saying innocent people don't pay people off to make issues go away, but I'm more inclined to believe someone if they maintain their innocence and don't take the easy way out, which is what Zeke has done.