A numeric example:

You and I have a channel on hivemind, we each put $1000 into it. We make 100 bets over a year-long period, each with a $1 fee, so there are $1900 left in our channel, all of it is on your side, because you kept winning bets more than me.

We each lock $100 into an ethereum contract promising to settle the hivemind contract at a sequence number of 1, and with the final balance of $1949 on your side, and $50 on my side.

The total amount of time $200 was locked up on ethereum is as long as it takes to close the channel on hivemind.

Case 1, we are both honest. on hivemind you get $1949, and I get $50, on ethereum we each get our $100 back.

Case 2, exit scam:

After we make the agreement on ethereum, I try to finalize the hivemind contract at the step where I had $950 and you had $1049, (after I had lost the first bet).

The ethereum contract locks our $200, and refuses to give it back.

You provide the guilt transaction. Hivemind gives you $1900, and it gives me $0.