Warzone Player Highlighted blue

[Bigurn]

So every now and then when I view a kill cam I see someone who is downed highlighted blue being revived (or bleeding out) either way they are blue. The only time I have seen players blue (or any color) has been from the wall hacking babies, could this be a sign of a waller or a glitch in the game or? Can't find any information on it online really other than someone mentioned it happened to their buddy while he was alive and that while he alive and shaded blue he could be "revived" so they quit the game because of fears of being called cheaters...I immediately thought stem glitch