This yellow player is a cheat.
The red and blue players can confirm it.
During the match this player had his European border broken by the red player. He then left the match and allowed the computer player to continue for him. Everyone played on and I got taken down to my last couple of men. I had a grudge against blue and so I ensured that red would be able to pick up my 4 cards after the bot played for yellow. But no. The sneaky cheat yellow all of a sudden after 6 turns of not playing was back. He picked up my four cards.