I suspect Mike Jones' decision last weekend not to issue red for the high boot was that he's met the FA panel before, when Delap's red card was rescinded (from 0:45):
As to VC or SFP, Aguero was retrospectively charged with VC for this:
(NB Reid put his hands to his head but went off holding his throat...) Are we really saying that the interpretation of "challenging for the ball" could mean the FA would say that the way the referee described it was wrong so we're allowing the appeal? I know the FA can be daft, but not that daft surely.
Does it make a difference that it was use of an elbow (though the elbow missed) rather than (in the Lansbury case) a cynical kick from behind "while (not) challenging for the ball"? (Don't forget the current phrasing of the law started when
any tackle from behind was made SFP as inherently dangerous.) Perhaps the obvious distinction (SFP/VC) should be the same as a trip for DOGSO in the penalty area - was there a realistic chance of playing the ball? - yes, yellow; no, red.
The VC wording of course allows for an attempt to use excessive force or brutality - but I really don't understand the concept of "excessive force while not challenging for the ball". Presumably the same action (as in the Lansbury case) could be SFP if the opponent had the ball, but VC if perpetrated on an opponent running off the ball hoping for a pass. For all the tinkering, the wording is still silly, and a lot derives from the "excessive force" wording.
VC seems to include an attempt to use excessive force, but "a player who, when not challenging for the ball, deliberately strikes
an opponent or any other person on the head or face with the hand or arm, is guilty of violent conduct unless the force used was negligible". So an attempted head butt or an attempted punch is VC, but you can deliberately strike someone with negligible force and that's not VC.