There is oil mixed in with the antifreeze fluid in my radiator. Why?

What is your question?

I recently had a neighborhood mechanic replace the power steering pump, altenator, and radiator fan in my Trooper. Also, he told me my transmission is starting to go bad, and did a "transmission tune-up". My theory is that some mechanics SAY they know how to work on foreign cars, but end up experimenting instead. Could he have done something wrong?