He does have proof, the chat logs are enough to serve as a binding verbal contract and would be suitable in a court of law as far as I know.
Stop being intentionally obtuse.
Speaking as a lawyer, yes, you are correct. There's, at the very least, a verbal contract here (well, depending on how the terms were originally communicated), and depending on how much of it is in writing on Facebook, it's almost definitely a written one, too. It doesn't matter that it's on Facebook -- it doesn't have to be on some sacred legal parchment. As such, the dude's clearly in breach.
I was bored, so I wrote Dred's opening statement:
Cameron, lil bitch, he ain't got shit on me
Comin' round here trying to roll on my FANmily
Kid says I stole a hundred bucks
Bitch please, I don't give three fucks
Little hopper just spreadin' lies on the internet
You want your pocket change, bitch? I spent it.
ARF ARF
this cartoon dog'll kill you with a right hook
It's watchu get when you think you can spit on Facebook.
Seriously, dawg, we all can't even stand ya
You're like a doofier version of George Costanza
Oh, I'm sorry; was that reference from before your time?
Whatever, infant, you ain't gettin' a fuckin' dime.