One possible reason might be that he is double NATting, I have that and it kept causing one of the other team to leave and one match it forced me to leave, this only happened on my hunter and not my Titan (didn't do trials on warlock). I also have problems matchmaking because one min my NAT is open and the next it is closed. I'm not saying this happened to him but it is still a possibility. It occurs when the NAT type on the ps4 is open but a game interprets it as another(eg closed) I was restricted from trials and crucible and understand why it is suspicious so I don't complain, in the meantime I shall be playing remastered, yours sincerely... Urrm how do I end this... Me :)