Jay your thought process is not quite right here OIL based primer is the best underlayment for Latex (water based paint) Once dry the Oils are stable unless reactivated with another oil. So Oil based primer and Oil based paint is "NO..NO"
The Oil in the top coat of paint removed the adhsive property of the primer and makes a muddy mixture. Latex over Oil is ideal. Correct Oils and Water don't mix, and thats a good thing. Oil and Oil do and thats a bad thing.