So I was speedrunning the Halo 4 campaign with a couple of my friends tonight. We finally got to the last mission and were about half way done with it when a message came up saying that we had "lost connection to the other players." Wtf does that even mean? It sent us all back to the Campaign lobby together. None of us were lagging and no one disconnected.
That was a Halo 3 con.
I haven't seen or heard about it since Halo 3 though, as Bungie fixed it in Reach and let players drop as they please without ending the game. Odd?