80 isnt terribly bad as long as they are all even. But you would think they would just set it at 76 and make it right. Or even better, use the torque sticks they probably already have, which are color coded and made for specific makes of cars (there is a 76 lb torque stick, in most sets AFAIK) if they use those instead of a tq wrench.
I dont take my car to tire shops any longer. I take the wheels. Too many bad instances, and most of them around torquing the lugs properly. The last place (TiresPlus in Golden Valley, MN) ran then down with an impact wrench with no tq stick. Of course they claimed they used them, but when my 180 lb self has to stand on the end of a 1 foot wrench to break them loose right afterward, it is pretty obvious. Destroyed the lock one one wheel and the key (McGaurd). They ended up having to buy me a new set of locks after I came back, visibly upset. It also took the guy 4 hours to mount my tires, which is just plain ridiculous.
Its not a discount tire, tires plus, etc thing. It is the person working there. I dont care how much training the company has going on, you will still run into this.