Hmmm, this seems to confirm my own theory as to why the quest ended early. Mind you, it is theory only.
Although the items are "virtual", they still take up space on servers and databases. Take a look at the prizes that included two rather complex magics. When putting this quest together, the programmers had to have allowed "X" amount of space on the servers for "Y" amount of players at any given time using "Z" type magic. Based on the difficulty, they probably made a statistical estimate of how many players would get through a very difficult quest, added some extra for a few more than expected, and then started up the quest.
First surprise - they may have underestimated the ability of determined VMKers to work together to get through the quest. No worries, the "extra" cushion they added would accomodate that difference.
However, if you have a few who can hack in to strip prizes (that is, force the database to spit out prizes faster than anticipated), it may well have caused serious programming issues. Some of that really bad lag last night may have been the result of that. It's been a long time since I've had serious dc issues on VMK but last night was horrendous for about two hours. Then it stopped suddenly. A hack or series of hacks is literally an attack on a computer and it shifts resources to protect the program.
Let's go back a couple of days to the sudden addition of the cheater warning. This has happened before (Narnia Teleporters, massive downloads of codes to try to get Sparrow) and, sadly, no system that goes out "live" is completely safe from hackers.
My theory is that VMK put out the warning, some may have stopped, others did not and suddenly the programmers realized that the quest would need to be terminated earlier. I know some of you are wondering why they couldn't just add "more virtual prizes". Programs don't work that way. The only way you can edit them (e.g., add prizes) is to terminate them. Those who run the quest kiosk know that you can't change the quest once it is running. You have to stop it, enter edit mode, add prizes, make changes, test it again, and the resume. That is a program. That is how it works.