Can that many tickets physically be sold by 9.04am? I don't think so. I'd really like to know where those tickets go!
If my understanding of the system is correct, tickets usually are not offered for sale all in one go, but only a small batch (say, 2000, for example) at a time.
Once the current batch gets sold out, they'll release the next.
So by 9.04 AM almost all the tickets were probably NOT already sold, but simply withheld (sp?) for later sale, only a small part of them being actually available at that time.
Which sectors of the venue will be available in each batch is the promoter's decision - I suppose strategies may vary widely.
(... any way the wind blows ...)