Hmmm.... I was just surprisingly awarded my 60,000 points... According to my records, I believe I only spent about $4,500.00 ($500.00 short).
I think my spending does go over the $5,000.00 threshold if you count the $550.00 annual fee. However, my understanding is that the annual fee does not count towards purchases.
The $4,500.00 that I am counting includes "zeroing" out my TSA charge and my airline gift card charges (all of which were credited to me, which is why I zeroed out when trying to compute my spend). Maybe, based on the OP's discussion with the Amex CSR, they don't immediately remove credits and it's part of their review process.
I have two Platinum cards, so as soon as I saw the 60,000 MR posting, I switched to my wife's Platinum card so I can help her get to the minimum spend. I assumed that once my 60,000 points posted, that they were there to stay... Now I am a little concerned... Maybe I need to go ahead and spend another $500 or so to get my spending up past the $5,000.00 threshold (again, according to my records).