Stealth players in BoP

[KAV]

Howdy chaps

The other night me and McQ where setting up a strike session in SIM.
We where to do some recceflying ahead of the tourney.
In Lobby a third person joined, which was very ok, since me and McQ then could team up and be able to talk as we flew.

After launching the game, we suddenly spotted a fourth plane on the map.
Checking the player list, the opposing team consisted of only ONE player, namely the one from pregame lobby. On approach we, were able to kill the STEALTH and got an ID onscreen. After the kill, it still didnt appear on the player list.

Checking the PSN ID the player was "fresh" to BoP, but the flying indicated otherwise.
So the question is, Are there ways to "cheat" the game settings, to do stuff like this, or is it just an occasional game error ?