The only time you would need to disconnect the pitch links during a Track and Balance was if you were zero-ing the blades to start from scratch, in this instance the scissor link would need to be disconnected to allow removal of the lower pitch link bolt.
From the information that I have this did not happen with this aircraft!
Coconutty:
IMHO, it would depend. IF it were missing then yes, I think it would have been noticed on the Check A. I am not really sure if/how you could incorrectly assemble it?
B.U.D.G.I.E:
I would agree with Quichemech, the implication of your post with regard to the attitude of engineers is indeed FAR below the belt, and frankly uncalled for.