I think it's pretty clear they had their exploits worked out and ready to go for some time, and were just waiting for the contest to start to unleash them.
Seems like they found a real-life exploit created by the contest. That seems appropriate!
What's with this trend recently to build everything on fundamentally sucky technologies?
In order to evolve, platforms need their boundaries pushed. I'm sure this project is partially intended to reveal to browser makers (including Mozilla themselves) exactly where and how their platform could improve.
"Roman Polanski makes his own blood. He's smart -- that's why his movies work." -- A brilliant director at "Frank's Place"