they can, by choice, not bleed. This can also indicate the idea that for some reason the other person could not manage to hit them, as opposed to hitting them but not making them bleed.
Guy2: *does not bleed from being shot* “I ain’t got no time to bleed, fool!” *busts a cap in Guy2*
You attack Dude1 with your Rusty Iron Sword and miss! (279,500 hp left)
Dude1 attacks you with his Demon Sword and does 524,258 damage! (0 hp left)
You have died!