No he didn't. Sure, he may have lied to Kaiji and almost framed him, but it was over a petty amount of money. It wouldn't have ruined anyone's lives. Kaiji was in so deep, that amount of money was child's play. Besides, it's not like they were even friends.
Sahara proved he was still a human when they were on the beams. And he overcame everything and made it to the other side out of pure will power.