Users would be silly to believe he has insider knowledge in the 1st place. If he did, he would never have lost 1 bet and of course he lost multiple. He is just a normal tipster who was guessing match outcomes and yes trying to defraud by claiming fixed.
He did mention send him half your winnings but never really demanded it, he just kept posting more picks. I would just ignore the user.
There are a few members that actually attempted to bet. I don't know how they were so naive to believe in this stuff.
This guy in particular seemed to be extremely interested after winning the first bet with the "fixed matches", potentially convincing onlookers along the way as well.
Anyhow, this is just a warning and a request for DT members to tag this guy. This is not a new scam by any means.