What the hell....

Today my bro keeps disconnecting from the servers, but when he managed to play one match(Ship TDM), everything became weird, the names on the score board disappeared, my bro's M12 (for the lulz) was replaced with a dry AK-74, nobody could see him and he couldn't take any damage, but still, he switched from GR to BL in a odd way and when he "kills" someone, his name doesn't show up, every weapon he picked up had infinite ammo

When we checked the replay, ive noticed that he suddenly disappeared in the middle of the game before anything happend.

What the hell?...

EDIT: the kills and deaths didnt reg