Ah, I saw this talk from a live stream! Really felt your pain but I think the audience was sympathetic. I took it as a good lesson to have a demo-fallback which also works offline, although admittedly that's not as realistic.
we did have a fallback which worked offline. the problem was that without wifi we had to rely on the iPad's compass (previously, with wifi i was proxying gyroscope data from iPod Touches tucked in the back of the iPad cases) - normally this would have worked fine. when we were onstage with so many cameras there was so much current flying around that the compasses went completely haywire and we were truly fscked. I wasn't kidding when I said on stage that if the iPad 2 had come out a week earlier we wouldn't be having any problems :)
