In the older days we used to add a little ATF to the crankcase at each oil change to help clear out the sludge. It worked great, but in the newer cars with the special additives in ATF I would be hesitant. That said, i just surveyed several of the master technicians here and they say that if you add one quart or less to the vehicle and drive it you still wouldn't have a problem. ATF is high detergent lubricant. If you filled the crankcase with ATF, it would have a problem getting up to proper oil pressure since it is such a low viscosity.

Did you get the facility to write on the invoice what they did? That will protect you in case you need to prove that their work caused a problem. You might still go back and have them document that info. if you left there.

That's just my dos centavos.

xfirepop