I was in a match where a player was invisible. None of our team could see them. Only noticed it because no one could figure out how our kiln was getting dowsed. At the beginning of the video you'll see them use the hourglass skill and finish off the kiln and then I luckily break them. Later in the game they are visible (see 1:30 in attached). My apologies for which bottle I happened to be using for this screen cap.
#Invisible Player
grand plover
finite folio
i believe i just had this happen to me. nobody on the opposite team was attacking me or going after me.