In John Wick, while resting in his room Wick is attacked by Perkins and he must defend himself.
As stated by Winston:
no business on Continental grounds.
Does self-defense count as business? Wick grabs his gun and gets information from Perkins, and he is shown to defend himself in his hotel room, however, Winston and John are friends and Winston might bend the rules slightly for John, for example, after being reminded about breaking the rules, Winston gives John Isoef's location at the Red Circle.
In the second film, the rule changes to no blood on Continental grounds, either way self-defense can be covered under the two rules, but is it?