Water or coolant slowly getting into the oil

Hi, I had my engine rebuilt and thought the oil looked bad so I had it analyzed and their report came back a okay, then I sent a picture. He said either water or coolant was slowly getting into the oil. Was wondering if you had any ideals, my mechanic lost interest as soon as I changed the oil after the 20 minute breaking. There is absolutely nothing wet on the outside compression test was 165/175 except on 5 and 7 they were at 150 lbs, have changed the oil 8 or more time in 2000 miles going 300 miles at the most, crank bearings showed a little wear, mains looked new.