Why did the balloon attempt fail?

Since the early hours of the morning the Qinetiq-one team had been carrying out final checks and they’d started inflating the balloon. But as it was being rolled off its drum the balloon twisted and the helium at the top of the balloon came under immense pressure, causing a seam to split. As there was no spare balloon and not enough helium, the attempt was aborted.
    Brian Jones, Mission Controller of Qinetiq-one, and the holder of seven world ballooning records himself, says they’ll keep trying. The balloon will now be taken back to base and thoroughly checked. Ironically, the expensive technical equipment seems intact and the weather conditions are perfect.
    The team say that a structural failure like this should be overcome, but as they’ve now missed their weather this year and they’ve to wait till next summer to try again.