Raymond, it doesn’t seen like you have a complete grasp on how handicaps work. The system is designed to judge players based on their BEST potential scores, which is why it takes use of the lowest 10 differentials from the last 20 scores. It is not meant as a direct “an x handicap gets x number of strokes”. Playing on those same course and tees in Flight 7, it wasn’t too hard to look up the slope and ratings we played on.
Long Bay white tees are a rating 137, which means as a 28.6 handicap, your son was granted 35 strokes. This means his 102-35 was a 67, or 5 strokes net under par. His differential ((((102-70.6)×113)/136) for that round is a 25.9, almost 3 less than your son-in-law’s handicap.
Combined with his scores at Sea Trails Jones, with a lower rating of 125, good for only 32 strokes, he should probably not shoot another 99-32 net 67, again a differential of 25.3, or more than 3 less again.
The probability of him doing so, is so mathematically improbable that theres no doubt that his handicap is incorrect at a 28.6
What I do have a problem with is the tournament DQ’ing sandbaggers. Yes, I appreciate the effort put into by Scott and the to make sure Flights are won fairly, but people still spend a fair amount of money to come down and play to be banned from playing all 4 rounds. I think a heavier hand of adjustment to a finish outside of the top 10 would be perfectly fine.