Here is what i got from the golf digest labs on golf odds, the first one is close to what he did with just adding a extra round. Did not see those exact odds.
Two aces in a single round, same player: 67 million to 1
Three aces in a single round, same player: 2 trillion to 1
A player making an ace in a given round: 5,000 to 1
Acing a designated hole in a single round: 20,000 to 1
Acing the same hole more than once in 1,000 rounds:1 in 200
Getting an ace in a 1,000-round career: 1 in 5
Getting an ace in a 5,000-round career: Almost a sure thing
Two players, same foursome, acing same hole: 17 million to 1
Two players in a field of 200 acing same hole in a single round: 5,000 to 1