This guy takes a hit and blood splatters to the left of his screen, but takes no damage.
This is him sharing a recording from his Nvidia Highlights, not a replay. Also no damage to helmet or vest

I know it's common to land hits on enemies, see blood, but then going back to their replay and not see the shot register, due to ping and desync.

But I've never taken a hit before, saw a blood splatter on my screen and did not take the damage from it.

How is it possible this guy took a hit and did not get damage?