The fact that he was caught flat-footed isn't a surprise. My guess is he thought he had all the leverage in the world and there was no risk to change, unless he was the one making it.
As for hiring Shafer, or Hackett for that matter, perfectly reasonable thing to do. Shafer was a proven coordinator, had been integral to rebuilding the program, including recruiting.
As for judging his performance, the whole needs time "his guys" is a bit much. The guys already on the roster were "his guys". Also, he didn't inherit a disaster. The offense finished ranked 17th, the defense 48th. The team smoked a top 10 Lville team, whipped WVU, beat a SEC team in a night road game. The second half of the year it was performing at a top 20 level.
This job was not a rebuild, it was to continue improvement and development, he wasn't starting from scratch. He made one massively bad hire that has set the program back, hopefully Lester can fix it. The offense didn't need to sustain the level it was at in 2012, but it shouldn't have fallen off the cliff like it did.
I don't think he is safe, no questions asked. I don't think it's a forgone conclusion that's he out. But I'd expect he's under pressure to show legitimate improvement. There's more than win/loss record in that evaluation.