[@KillBox]

Strong enough that ignoring him is a bad idea. Even if they were even, or one slightly stronger, all that will do is partially nullify logia immunity, turning a headshot from lethal to merely brutal.

He'll recover, no permanent injury, but he'll have a hell of a headache.

As a note, Balthier's killing intent is low. This is pretty much just business to him. That will make it fairly hard for Observation to kick in, especially since Jōichirō's focus is elsewhere. If he was focusing on Balthier, and by extension, the gun, it would be a different story.

Also, if he's shielding himself with Haki, he probably doesn't have enough focus to imbue his attacks on Caitlyn with it. 

That is, in my opinion, the feat of a high-level user.