I just always assumed Chang was on the BOP when it fired on Kronos 1. When he messages the Enterprise and curses Kirk, I always thought even that was from the BOP, that they were just faking the static of the transmission.
The reason I thought this (and as a few others have mentioned to) is Gorkon saying "Find Chang!"
The reason I thought this (and as a few others have mentioned to) is Gorkon saying "Find Chang!"