Where the hell did that come from? No one blamed you for the emissions equipment failure. All that was requested of you is to make the repairs properly, without rattles, hassles, return visits or having to get medieval on your ass. Oh, and try to return the car with less problems then it had going in.
You know, this seems self evident, but, sadly, it's not. I've had the whole range of reasons to bring the car back to the shop, ranging from one fix revealed another problem, to not having the crankcase drain plug reinstalled. Yes, and the little red light preceded the engine welding itself into junk by about 30 seconds. *sigh* The garage did replace the engine.