The Romulan may have been military but he wasn't Starfleet meaning Crusher's orders had nothing over him. Further we're shown and told, in this very episode infact, that Starfleet isn't one to force medical procedures on people. It's naturally hard to really know or say what protocol is in Starfleet in a situation like this and it's even unlikely that Starfleet has protocol for this type of situation. But here we have a patient who'll likely refuse treatment and we have a donor refusing to donate.
Seems like Crusher's choices have been made for her.
It's telling that despite Galorndon Core being a politically explosive situation, Picard still decided not to order Worf to comply despite Crusher haranguing him.
I kind-of find it odd that in this episode a "special circumstance" couldn't be made to allow the Romulan ship to come to the planet. I mean apply restrictions like them not being allowed to cloak, take a direct path, all of that and then they'll be escorted back to TNZ. But it seems like this is a case where both sides could have worked together to find an equal solution.
But, then again, that was the point of the episode. While Picard was fighting with Tomalok (SP?) in space over procedures and how to do things, Geordi and the Romulan planetside after some initial struggles learned to work together and save themselves. Especially given that the planet's effects had disabled Geordi's VISOR and was messing with the Romulan's nervous system. It's that kind of thing that made me really like this episode.
But Picard in this episode almost seems uncharacteristically irrational given the situation everyone was in. You'd think, being a diplomat, he'd see that it'd be better to allow the Romulans restricted, controlled, access tot he planet to save their citizen, rather than letting the guy die under his care because he wouldn't let him get the help he needed.
The first option is an unfavorable one but it's one that could have prevented a mess. The second option could have led to war or at the very least increased tensions between the Romulans and The Federation.
And while it's "the point of the episode" for Worf to be the perspective donor I find it hard to believe there's no Vulcans on the ship who would have been a potential, and closer, match for the transfusion the Romulan needed given that Romulans and Vulcans have a vastly closer genetic relationship than the one between Romulans and Klingons.