I see John snapping in this verse. I don't think that he would do it now...but maybe when events get worse...I do see it going to happen.
And I'm not sure if he'd regret it later...if he could be fixed.

...I don't know if he'd let Rodney live...or maybe my interpretation is darker than yours.

But I definetly think that this version of John has got that violence much closer to the surface than most.