Theus absolutely shouldn't be worrying about the W-L record, he has very good job security regardless, if only because he isn't hated. Not by the Maloofs, not by fans, and as far as we can tell, he hasn't lost the team. I'd go so far as to speculate that he might be the Maloofs' favorite coach ever. With Muss still collecting checks, that means really great job security by NBA coaching standards.
He has also given us a chance to see more clearly what is wrong with the team. Two years ago, people could (incorrectly) believe that the real problem was with Adelman. Last year, they could easily believe it was with Muss. By now, it's clear that nobody could take this roster very far. All Reggie has to do is to keep losing gracefully, and to keep the players from coming unglued while the FO take their sweet ****ing time about rebuilding. That, alone, is quite a challenge, but I think he'll probably pull it off. It would take quite an explosion to overcome all that good PR.