If the clutch on a car was new would it be normal for it to smell.

I had a new axle on the right side on my car installed and now my clutch smells bad, when driving it. The mechanic claims he also installed a new clutch and redid gearbox oil.

Any clues?

I also cannot understand why he touched my clutch, I am more worried he changed my gearbox, because when I left I saw a gear box next to his car.