Hi, I was hospitalized in March by my pulmonary Doctor, because I had a Blood Ox. level of 74 that was really low. In the hospital they told me the norm is between 92 and 96. I was eventually diagnosed with "Boop Pneumonia" its long and complicated, but apparently it is related to the fact that I have Systemic Lupus. They are treating it with high doses of prednisone, and I am on oxygen 24/7.
Your friends dads blood ox sounds like a normal high. They take a reading while you are at rest, and then after walking, or some form of excercise. He should be seeing a Pulmonary Specialist, to have it monitored regulary. But from what I was told, thats not a bad number.
Hope all works out for him.