Wasn’t McMaster a baddie?
My theory;
I think McMaster was a deep state plant. I further think that the whacking of his daddy was a message to him and others. McMasters either had second thoughts and wanted out or was confronted by our guys, and stepped down. Either way, the Deepies see him as a threat. They think he flipped or might (has) give(n) them up.
So, they whack the papa to keep him on the team, so to speak. Also to let any other potential filppers or rats know the consequences.
That's what goes on in my fevered brain. Cause I be knowin' thangs. :)