There is 2 ways to see how this bug works out:

NON lagging player-
Sees player running in a straight line, non moving.
Player that appears to be "running in a straight line" is actually right next
to the player. Also a chance to see the fake running player go through walls.

Lagging player-
Sees people freaking out due to not being able to see them and they are able to see the player that's freaking out. Not sure if other player can hurt the player while invisible to them.