I just need to post this. The plot bunnies that went through my head when I read the comment posted with it...
God, the look on his face here - that smile, that absolute feral smirk when he knows the bulletís connected, and the shot is fatal. Iíve seen meta suggesting this is where the programming breaks down because how could the Marvel universeís deadliest assassin miss, but to me thatís not at all whatís happening here. Buckyís just been strangled unconscious; heís likely still stunned. Steveís dislocated his human shoulder and twisted and warped the plates on his left arm in their previous fight. Bucky isnít missing because he wants to; heís missing because heís stumbling, dizzy, unable to aim. Heís missing because his arm isnít stable. Look at that third gif; heís in pain as heís shooting; the blowback from each pull of the trigger is making him wince and heís having trouble keeping his arm steady. And through all of that, despite the fact his body ó his ultimate weapon ó is failing him, this is still his mission. More than that, the mission is personal. That, above all else, is where the programming is cracking: the Winter Soldier isnít supposed to think in terms of personal; he isnít supposed to want for himself, even if that want is violence, is retribution. Heís supposed to follow orders, and in this moment, he wants to cause harm to someone whoís getting the better of him. Tit for tat. He feels threatened by this man whoís making him feel, and he wants those feelings to stop. And heís willing to push his broken, twisted body to the breaking point to do it.
We see this again, not long after, when he breaks down farther, is left backhanding Steve, repeated, distressed and sloppy hits that donít mange to kill him, despite the fact that earlier we saw a single punch destroy concrete. In those final blows we can hear his arm squeaking, plates grinding against each other - we get a real sense of how damaged he is. But heís fighting, not on the orders of others, but because the things Steve is saying are terrifying and he wants them to stop, no matter the cost.
And now compare this ó how damaged he is physically, how much pain heís in, and how much of that pain heís willing to ignore if it will make the main causing the chaos in his head stop talking ó to what he must go through, jumping in to the Potomac after Steve. Using his crushed and warped left arm to pull him to safety; using his dislocated right arm to move both of their bodies through the water. The amount of pain heís ignoring to save Steve; to save something important to him; to complete a mission of his own choosing. And itís completely, wholly altruistic. He walks away: injured and without any concept of his own identity or where he should go from here. The man on the ground ó heís the Soldierís only link. Someone whoís repeatedly offered to help him, to save him. And the Soldier stays only long enough to make sure the manís still breathing, to make sure heís in clear enough view to be saved by his own team, before disappearing again.
For seventy years, Buckyís entire existence has been a backdrop of pain that heís learned to wear like a skin. But that moment marks the first time heís used his resilience against it for his own ends, against those who have made him into a weapon of destruction.
I will never get over this final scene.