Seen that many times at a shop I used to work at...usually though, it's the customer that just pad slaps over and over again...till the rotor is gone. That, is not a improperly installed rotor...you can't get everything back together if the rotor is on wrong...even if it's the wrong rotor, it wouldn't wear like that.

The worse I've seen was a 1989 Caddy that was down to the veins...and she DID NOT have the work done cause she didn't have the money. Needless to say, I did the work for her for free...I was not gonna let her drive out with NO brakes, possibly slamming into some innocent soul.

People...really, amazing.