1996 Lexus ES 300 Power Windows

1996 Lexus ES 300 6 cyl Automatic 100000 miles

I took my car to an import shop. Among the things they were going to fix, they were to look at the passenger front window. I was told the motor was bad. They took the door panel off to look, and now there is no power to that window, or the the 2 rear windows. Could this have happened before they looked at it, or do you think they dislodged something? Of course, they deny that it's their fault.

Thank you,
Jaylyn