You can't win the Heisman in Week 1 and you can't lose it either. The season is a marathon, not a 40-yard dash; only a long body of work can secure or forfeit football's most famous award.
But while the Heisman can't be lost in Week 1, it can certainly go from plausible outcome to pipe dream. Especially for players whose teams played a prime-time game, one wanting performance could be enough to cripple their stock.
It's too early to call time of death on their Heisman stock—sure. But the nurses are sitting by its bed to monitor.