Does this help at all?
http://www.scriptasylum.com/rc_speed/lipo.html concentrating on the balance wiring diagrams. It's hard to see just what happened without seeing the equipment , but I'm gonna guess first that you had the two balance plugs reversed. The left one was in the right slot and vise-versa. In any case it can be repaired and as long as the cells are in balance then it can be used that way. I doubt there's other damage beyond the balance tap wires , and it may even be burned off inside the pack.