Tuon's reaction to Rand in their meeting reminds me a lot of people's reaction to compulsion (e.g. Moghedien compelling Nynaeve and Elayne. In particular, the reaction to taverenness is different: Verin remembers words of her fealty spilling out of her mouth before she knew what they were. People can sometimes channel the One Power unwittingly and use compulsion unwittingly (e.g. untrained young Verin). I think Rand might be tapping the True Power unwittingly and compelling Tuon. Real compulsion can't really be resisted, but maybe not an unknowing small nudge. That increasing dark shadow hanging around Rand might be a sign of continued use of TP.

PS Sorry the references are a bit murky. My friend stole my copy of GS immediately after I was done.