burning smell after replacing ac compressor

i recently had to replace the ac compressor after the clutch went bad. now after having it replaced i smell a burning smell after shutting off the car. i smell after the ac isnt even running. i had found some oil standing on the top of a nut on the compressor and wiped off. but smell is still there. could it be that my mechanic spilt allot of oil in refilling the compressor?

Any grease or oil on or very near the exhaust parts will smoke and stink until it burns off in a coupla days of driving.