You don't touch the knees of other people full stop (unless it's your spouse in bed kind of thing)
Really? Touching each others knees in bed!? Funnily enough that isn't the area I normally go for - seems rather niche!
I would have thought knees were innocuous. If I were touching someone in a kind/making a point, non sexual, making human contact, in no way abusive or sexual or threatening way I would probably choose knee if we were sat side by side as they were. Or if I were facing them then possibly the hand or arm.
What the woman was doing in this clip (as so many previous posters have said) was attempting a connection with the top of his hand, which he didn't realise until he pulled away, then he repeated the action so she could complete it. She did not remove it or attempt to remove it, that isn't what happened, have a look & for the love of god please STOP LISTENING TO THE DAILY MAIL talking utter shite and making stuff up!! It was awkward (because of the misreading) but totally not an issue as she herself has said in a subsequent interview, and I believe her, I would also be totally fine with someone doing that (although also cringe at the awkward moment, as I do when you do the move out of the way dance and both go the same way), it is a non-issue.
All this outrage - as both myself and previous posters have pointed out totally devalues and minimises REAL abuse, it is not constructive and is really quite saddening.