Just to add my two pence worth...
AUH is spot on - The stopping actions MUST have been initiated by V1 (See Boeing 747 training manual)
Glueball spot on - anyone who rejects a takeoff after V1 is stupid (The only exception being if there is absolutely no way it will fly!! Very rare indeed)
Cessna 120 - I agree with the exception that however "slightly" after V1, with all the will in the world you will not stop on the paved area on a balanced field departure (Basic rules of Performance A) 6 seconds, or whatever it might have been, is a lot of runway behind you!
Best regards
CL747 (current 747 jockey)