Are you sure they actually did the work?
My son is both a licensed auto tech and a licensed heavy vehicle tech.
He got his journeyman license working for a general shop then he worked for a dealership for a while. The stories he told me would bring chills to your spine. Like, the time he went to the service adivisor at the end of the day to say he didn't have time to do a coolant flush on a car. Both the shop foreman and the advisor told him "yes, you did".
He decided to get out of the light duty and went heavy duty. Now he fixes Caterpillars, John Deere, Komatsu, etc.
Nope, I'm not.
2011 Mustang 3.7L Premium Pony Package
2015 Silverado 5.3L 2LT DC Z71
1965 Mustang C Code Coupe 289/T5/3.25
1967 Chevrolet C10 350/700R/3.73
1967 Firebird 400