Book, I knew he was gonna go eventually as soon as I figured out he was an Alliance general. Wash tho, kinda a pointless way to go. Apparently Whedon is big on killing off characters.
I thought he was an "operative". Like well... the other "operative". (I don't think he's ever given a name...)
Even if he was a former operative, he wouldn't have gotten the first class medical treatment that fast and discreetly, with no questions asked. Book was a soldier, not an assassin. Book wasn't brainwashed into a particular ideology, he had too much military history knowledge, wasn't supremely skilled with weapons or martial arts, does not have combat reflexes, does have knowledge of tactics and strategy, etc. He wasn't a line soldier, otherwise the morality of killing the cop wouldn't have bothered him for a second and he wouldn't have known about the operatives. Has "retired high brass" written all over him.
The series never gave any hints, but if I had to make a shot in the dark... I'd bet a dollar that if the show had not been canceled, we would have found out Book was Alliance brass at the Battle of Serenity Valley.
Either way, we'll find out soon enough. "Serenity: The Shepherd's Tale" comic is coming out.