I hate taking up the mantle of Cochran-bashing, but this player deserves it. He's neither hero nor villain, makes no big moves, is infamous in his own mind, plays for "3 more days." The logical comparison would be to Sandra (whose strategy was "anyone but me,") but she built alliances, dumped fish, manipulated players... What he's doing is a waste of space on this show.

they didn't save him
Whether their intention was to save Cochran or not, they did "save" him each time. Ozzy volunteered to go in order to have all 6 players survive to see another day. If Cochran wasn't going to stay loyal, then Ozzy wouldn't have needed to do that. "Good luck on Redemption. Thanks for losing the challenge for us."

What could Ozzy have done differently?
He's certainly not blameless. He could have offered the idol to Cochran instead of Whitney. He could have had Jim sell the plan (he's a salesman! AND plays poker! TOTALLY the better choice!)

Worst part of Ozzy's plan was that it didn't appear he tried to bring anyone over (as a back-up plan) from the other side. He just assumed they were tight. Had he spent a moment or two analyzing the situation he could have reached out for the outsiders.

Did he realize that Cochran really had an issue with pulling a rock out of a bag? He didn't, but he should have.
I disagree, to an extent. The plan was solid. Big moves are rewarded. 85% chance of being safe (1/7) from RI. Everyone else was ok with pulling the rock.

And yet he still did not want to draw a purple rock and be instantly gone from the game. He would rather take the game into his own hands then to lose that way.
The game wasn't going to be in his hands regardless. The winner is voted on by people they've kicked out, not by the person who lasts 39 days. He'd still be in the game via Redemption Island, so even if his goal is "3 more days" he'd get that on RI. I understand that the purple rock is an awful way to play - but it's still only been done once in 23 seasons, and 7-10 other people in the game were willing to go that route... shouldn't that tell him something? That's what irks me the most, I think - he's not a very good student of the game. His chances are 85% of not drawing a rock, and then significantly improve in winning the game by not drawing the rock. And he was already scheduled to get kicked out anyway - these are all free days for him!

"Thanks for saving me, suckers!"

...actually, that would have been a fine response. Instead he turns and says "Yeah, it was me, but I can explain." Like, he's trying to be the hero, but keeps doing villainous things... and he's not being a villain for villain's sake, either!

I feel bad that he's insecure, and I'm sure I'd probably be in the same exact boat as him if our places were exchanged, but that doesn't make it right. This guy has overstayed his time on the show, and makes stupid mistakes - I'd like for him to leave now.

...and I can't ever remember feeling this way about any other player.