Do shops still sabotage cars for profit?

I tend to think a little of that still goes on these days unfortunately. Not long ago, my GF took her Olds Intrigue in for a routine tire rotation at the local Goodyear Tire "big shop". She was already a returning customer. I dropped her off so she could drive it home. The Olds is ready to go in the parking lot. I notice that both front tires look a little low on air. I snap a tire gauge on them and they have around 20 lbs in them. Slightly miffed, I go in and tell the guy at the desk that they're a bit low on air. He takes care of it but I'm thinking, hec, I could see maybe one tire's pressure overlooked but both? The guy that did the rotation was either the stoner of the day, or made on honest mistake, or hoping she comes right back as a result of the car driving funny.