It looks like there is a slight problem with assists of desintegrators. In the game we just finished my kind team mate got 57 assists. I somehow doubt that we had that many enemies. 
lol… maybe he just hit the carrier. *g*
Is it just a display bug or did the system really thought your mate had 57 assists? (I mean, did he get a mission reward equal to 57 assists?)
I can’t tell you because I didn’t ask him. (The chat system isn’t that hot.) IIRC the player in question goes under the name “68”.