about shiro not backing keith’s story in bom: i think there’s other factors that a lot of people overlook. namely, the fact that shiro’s response isn’t just him reacting to an isolated incident–its him finally putting together the pieces after a long time of dealing with constant doubt and concern. because he knows something’s up with keith. in season 2, he’s the only one that does. on two separate occasions, he takes keith aside and tries to talk to him, to ask him what’s wrong, to try and get him to open up. and every time keith shuts him out? you can see the fear on shiro’s face, can see that he feels like they’re slowly drifting apart and he’s losing keith
these two strike me as friends who probably used to tell each other everything. so the fact that keith is refusing to talk now, that he’s forcing this distance between them? shiro doesn’t know what to think. and when he sees keith has this alien knife and is maybe part galra? maybe isn’t even from earth at all? shiro is very quickly finding out that this person he’s very close to, someone who he thought he knew everything about, is quite literally becoming alien. his best friend is suddenly a stranger, and he’s questioning whether he ever even knew him at all
looking at shiro’s face here, he looks just as panicked as keith. despite how good he is at improvising and acting, he doesn’t even have it in him to scrape together an excuse or cover story. he’s genuinely shocked, and just blurts the words out without thinking. “I…I don’t know”–he hesitates, stumbles. he’s seeing the person he thought he was really close to in a whole new light, and he doesn’t know how to handle it
and keith? when he’s down on the ground, the first thing he says is “Shiro, you know me.” becuase he’s trying desperately to bridge that gap, to make shiro see–to prove that, even if keith’s going through some shit, even if he doesn’t know who he himself is, he hasn’t changed. the person shiro knew is still the same.
also, look at shiro’s face after that exchange. that doesn’t look like someone who just sold out or distrusts their friend. he takes the time to look at keith and kinda check in, to see how vulnerable and scared he looks (scared because he thinks shiro doesn’t trust him)
before he goes right back to glaring and confronting the bom
he then tells keith theyre leaving and starts walking away. he realizes there’s some kind of conflict here between keith and the bom, so he tries to separate them. if he really didnt trust his friend, he would’ve insisted he either 1 hand over the knife or 2 started asking a bunch of personally invasive questions–after all, this is the person that insisted on morally grey mind control interrogation to extract information from a galra.
instead, he sees how honestly hurt and confused keith looks, so he gives him some space and tries to quickly remove him from the situation
and when keith insists on staying? shiro’s worried look in the background there? even if he doesn’t understand what’s been going on with keith all this time, he’s clearly concerned, clearly cares. he backs off a bit and let’s keith say his piece, because he realizes just how much all this means to him. shiro doesn’t interfere again until after he hears keith’s life will be on the line, and immediately tries to get him out of there
he goes right up to keith’s side when he tries to reason with him, and we get a repeat of that shoulder touch thing these two do so much. shiro especially does this to keith a lot, and it honestly seems like a kind of grounding thing. he reaches out to keith, tries to tell him that whatever’s going on his life isn’t worth it, holds onto him to offer some kind of comfort. the way shiro tries to convince him here reminds me a lot of that thing joaquim said in an interview, about how “shiro is sort of the only thing that can really calm him down and keep him in check.” shiro very much tries to do that here, sees that keith is angry and upset and tries to keep him from making a reckless decision.
was shiro really taken aback and hurt initially? i think so, yes. but once he kinda has a bit of time to recover and think things through he’s still thinking of keith and trying to help him as best he can–this is also why he doesn’t try to stop him again until it’s absolutely necessary, because he respects keith’s volition and understands the importance of that autonomy. when push comes to shove, regardless of the situation, shiro still steps up to protect keith