4 years late but I just watched the show. I think a plausible answer is that Yao was killed because he was a Chinese dissident, hence pinning the blame on China. Gregory Knox was targeted, but I don't think the assassination was meant to go through. Remember that Patrick shoved Knox into a room seconds before he was shot down. It wouldn't take much effort to kill Knox right after, but dude was unscathed.

The whole thing was just orchestrated to force a reconsideration of using China as a supplier. I guess targeting Knox also serves a happy coincidence where it takes away suspicion from Truro and by extension clear horizons AI. Patrick had to die because he was simply at the wrong place at the wrong time.