My guess is starfleet would not allow him to do so on the flagship of the federation, if he was on earth that would be different. Likely did not want to take the chance they would deny him and since there seems to be no cure for her condition, he saw this as his only way to protect her and find a cure and did not want starfleet to interfere with it. On the topic of the episode as a whole, i enjoyed it. I am really liking the episodic feel to the show. and the ship itself, i love the redesign. As for Una.. Is she like part human, part illyrian and perhaps thats why starfleet did not realize or did she just never have a genetic test done in her career? I mean in ENT, assuming those illyrians are the same, they are depicted as not being some lost human colony as was suggested earlier in the thread.