Took my car in for oil/filter change and in some odd circumstance, the young mechanic managed to drain 1 liter of transmission oil out of my car (which I didn't know at the time). After driving for 10 minutes (~5 km), I noticed my reverse gear wasn't shifting properly. After ~30 minutes of driving, my car was smoking from the exhaust pipe (turns out he had overfilled my engine oil too!!).
<br/> Took the car back in to complain the mechanic supervisor claims my transmission is still fine and all I need to do is refill the lost fluid. Another independent mechanic later tells me my transmission line is likely fried if I had experienced what I did, and those guys should be responsible to replace everything.
<br/> Since fluids have been topped up, I have no proof of who is right. So my question is, if I only drove for maximum 50 km after my transmission fluid was drained and engine oil overfilled, would that be enough to cause serious damage to the car?