Board Thread:Questions and Answers/@comment-3250527-20140627033401/@comment-6697950-20140627072629

The 10 seconds is actually the revival time limit in SAO, that doesn't exactly mean that the NerveGear activates the kill switch right away.

Asuna is a bad example, since Heathcliff interfered and I doubt that he interfered after seeing Asuna die. The only time he was operating the window was right before the duel. He likely disabled the killswitch at that moment because he wanted a private chat anyway. Or, if Kirito had lost, he may have returned him to life because the duel was ahead of time anyway. Fact is, no one saw him operating any windows once the duel had started