Valeris tried to avoid the mind meld by backing away, but Spock grabbed her wrist and she didn't try to object any further. That tells me that she thought she was mentally strong enough to block Spock's attempt to find the truth. She was mistaken.Could, yes, but probably doesn't. Spock had probed the minds of several Starfleet officers prior to this incident (not to mention nerve-pinched or violently beaten several, even strangling one to death!). It's difficult to see any illegality to the act in light of this.Spock probing Valeris mind, could constitute an assault
On more general terms, Valeris' right to privacy of thought is debatable to begin with. No such right has been mentioned anywhere in Star Trek, and examples to the contrary are legion. OTOH, Valeris is Spock's subordinate in a hierarchy that further limits her rights from the civilian standard.
Nor is there any indication she would find it possible to resist the treatment, even though she shows no fear of speaking her mind or otherwise using verbalization to her advantage in this supposedly threatening situation. If Spock were violating her, or planning to, would she not point this out?
Timo Saloniemi
And it was as painful for him as it was for her.