I'm certain he thinks jl777 is the founder of the Ripple based insurance startup 'PeerCover', which I know is false.
Yeah, sure he isn't.

I'll bet you 25 btc jl777 is not Jared Mimms. We can use a recognised and trusted escrow.
I would love to take your money, and I bet you'd love to take mine.
If you're sure jl777="Jared Mimms" and you can prove that, take the bet.
We both know that I cannot prove that jl777 is Jared Mimms and you cannot prove that he isn't. Your bet is therefore pointless. It is my opinion that they are one and the same, but I don't know this with 100% certainty.