Every player, after a losing game, is in an irritated state.
The desire to leave the tournament, accuse someone of cheating, or something else is a perfectly normal reaction. What matters is how the person deals with it.
The tournament ends on July 17th. Juristis has only 2 games left. I'm sure there won't be any technical defaults, as there's a match against the previous winner (and you can score a prestige goal), and the situation in the group isn't hopeless.

And this: you can't force someone to play by threatening to punish them. This is a destructive path.
I suggest we move the further discussion to the Forum.