Some people (not you) seem to have no idea how libel law works. Let's say someone saw Moz do something very dodgy indeed. Saying you saw Moz do something very dodgy indeed could see you sued for defamation etc unless you had undeniable physical proof such as photos, text messages, or similar.
From my perspective, on a different matter, there was a guy who was defrauding a company, and upon investigation though we could get to a 90% proof level, we needed 100% to take the guy to court and prosecute him, so we ended up with a NDA and a sacking. That's how the law works. The guy who I worked with on this investigation said "There's a difference between what we know he did and what we can prove in court."
If someone was to go public and say Moz Did Very Bad Thing, they'd have to have enough evidence to prove in court that it was factual. That's not being complicit.