Did Captain Picard make an ethical error on the Enterprise?

Counselor Troi is in sick bay and has just reported being telepathically raped by Shinzon. She is clearly traumatized. She requests permission to be relieved of her duties to recover and protect herself (possibly leave the Enterprise to return to her homeworld).

Picard denies her request and starts blathering about how if she could endure more of these assaults it might be helpful somehow to the mission. Before they can finish the conversation (and Troi resigns from Starfleet as one might expect), Picard is abducted by the Remans.