This might sound naive/ridiculous but I trust Ryan Zimmerman. I feel like I have a pretty good read on people and I just don't see Zimm as the type of guy that would do this.
If he did cheat, then man that would shake my very foundation as a baseball and sports fan. I admire/respect Zimm so much and he's done so much for this franchise and community, I just can't believe he'd stoop to this level.