I have had this happen a few times where the game seem to split into 2 games. Happens mostly when someone drops or quits.
This last game we had a 5vs5 going and someone had simspeed problem and wanted to leave.
Then not too long after i were killing EVERYONE and i was like "omg this is too easy" and wrote the same thing and no one replied...
So i looked into tap menu and saw i was fighting AI's... and i who thought i were playing newbies
Personally i would prefer the game to stop, as if i wanted to play AI i would go single player