I have not seen the problem myself and my friends are not mechanically inclined. They did manage to say that after the water pump was replaced, they had to pull the radiator and have 8 holes repaired where one of the mechanics hit the radiator a number of time with his tools. I personally have replaced a number of water pumps over the years and never had the oil and coolant mix.
The motorhome is now in storage and my friends are heading home in a U-Haul truck, so they have solved their problem for the time being.
I appreciate all your comments as I was simply looking for ideas. As far as my friends being at fault for driving without water or coolant, I simply cannot know the answer to that. I the name of friendship, I will not bring up that possibility.
Thanks again,
Paul