Ive got a similar multiboxer v multiboxer story in av.

So i was in a turtle game and horde has us blocked in at the bridge and I'm just racking up kills when out of no ware comes 4 chain lightnings which is enough to kill at least one of the berris, I quickly kill the other two berris off to get full mana and to try again. As I'm rolling back up to the bridge I spot the other Mb'er but every time i try and make push for him 7 or 8 horde would make a b line for me and sure enough either i would die or the multiboxer would light me up while im snared fighting it out with the guys in the way. he had signifigantly less gear, and mobhealth said he had 6k hp per shaman but i just could get thru the zerg to kill him. we eventually lost and i haven't seen him since unfortenetly