I know
@MillionMilesAway has suggested this is as 'reasonable' as their suggestion, but I have to disagree.
The ref wouldn't be quoting the law back at VAR, he'd be saying WHY he thought this hit that threshold, so a conversation like the one you replied to would be much more likely.
The VAR needs to know WHY he thought it was excessive force, so that the refs onfield decision can be supported. If he says 'studs up challenge at knee height', and that's what happened, then, even if the VAR disagrees that it was worthy of a red, they should defer to the ref. If that's not what happened, then they tell the ref to have another look.
I'm surprised it was overturned - I think it was one where, whichever way the ref gave it (yellow or red), it would be upheld. I can also see that if we had the audio or an explanation, that would help a lot, but even before I'd read the post you replied to, I'd assumed the same kind of thinking.