can anyone help me with my 97 taurus

i had a new waterpump and new timing cover put on the car. a day after i got it back the car died on me. i found out that the antifreeze had mixed in with the oil. i checked the spark plugs and other misc items to see if the head gasket had blown but it doesn't look like it has.

Does anyone know if what was fixed would cause this if it was done wrong????