Actually, the temp in your car (even with your new tint and northern location) probably breaches 200 in the summer; hence all the dead dogs in cars. Still well within the nylon rating though. And no one gets hurt if that part fails (as you demonstrated already), so it's nbd. Just don't put one on your steering linkage too ;-)
Sure seems like the fella the replaced your master bent the hell out of that bracket to get it out and did a half a$$ job putting it back together. It's hard for someone who does that work everyday to be as dedicated to your car as you will be, assuming the skill is comparable between you and him. I can't even take my car in for an oil change anymore- too many minor mistakes like that just end up taking more of my time to correct than it's worth (spillage, overfills, stripped pan, etc.).