Unfortunate but not entirely surprising given the way steelerships, at least some, pay these junior tire changer/lube emps. Paid by the job, and not well, they are expected, need to work fast, in order to make a living wage and sometimes miss things as a result. In my son's first experience at a steelership, one of the techs sent a car out with no oil in it after the oil change. Customer came back after a few blocks when the oil pressure light came on and she heard ticking...
On 3 occasions i took our car in for service, only to find the techs did not re-install a under car shield that was removed for access to the oil filter. The first one i did not notice until i did the next oil change. The second (on a different car) i noticed as i got down and looked under the car for it, and it was indeed absent. Told the service guy and he did not believe me so i had him look under my car, then a new version of the same car on the lot, and the new car had the shield, mine did not. He found it in the garbage can in the tech's bay. He likely broke it trying to take a shortcut and only removing 2 of the 3 screws and bending the shield. They ordered me a new one and re-installed the old one.
Same scenario next time, except this time i bypassed the service guy and went straight to the service manager to explain he has a systemic issue in his operation, and while i was not factory trained as their marketing posters promote, i knew enough to replace all the parts i took off. Once again the shield was found by the tech's bench and re-installed.
Have not been back since now that the car is off warranty.