I theorize that Delta secretly shares IT systems with AmEx, in spite of their inability to do so with NWA. AmEx website shows my stats as follows:
Previous statement balance: $289 (correct)
Recent Payments: 5800 (correct)
Recent charges: 5640 (close)
Balance: 1447 (??? math ? )
My available credit number has no relation to my balance, outstanding authorizations or credit limit. I've occassionally seen it show as 2k HIGHER than my credit limit. Usually it sorts itself out if I wait 24 hours, much as your upgrade sorted out.
You were probably upgraded immediately based Y and therefore had zone 1, the coach seat assingment and touch-and-go on the upgrade list was an IT fluke. I suspect Gilligan didn't notice the hand on his back, as he probalby never considered who was below him on the list, just saw that he was #1, no seats available, he didn't clear. I only check the names below mine if I'm looking for someone else to clear who is traveling with me, otherwise I wouldn't notice that someone I didn't know who was below me had disappeared from the list, especially if the seat stats didn't change.
Hope you had a comfy ride! My spouse and daughter had connection issues HOU-ATL-IAD today because of weather, they are on the last flight out and we were afraid they wouldn't be in until tomorrow.