On the other hand, there are all these "experts" out there telling us it shows all the marks of a professional hit.

I don't think it really does. Basic things like I can't imagine for example a professional hit man not taking a second shot for surety.

But it's worth going through the actual known chain of events and evidence as given.

As stated below I'm not prepared to discount the idea that it was indeed some lone fantasist: it appears there's a breeding ground before every US youth bedroom laptop: manufactured by the identity mania which has been substituted for economic power politics for which both Democrats and Republicans are responsible and in which Kirk was a participant.

-Regardless, it was one hell of a lucky or unlucky shot.