Let us talk for a moment about how much Bodhi’s words in this scene affects Cassian.
Gif made by @stevenrogered and used with their permission.
Cassian just got off the space phone with Draven who reconfirmed his orders about killing Galen Erso first chance Cassian gets, an order that does not rest easy on Cassian’s conscience or heart.
We’ve seen Cassian struggle with what he has to do for the Rebellion since the moment we meet him.
His expression after he shoots his contact, to keep him from being caught and meeting an even more painful end at the hand of the Empire, is one of anguish and regret. He lives with it because he has no choice, because the Rebellion has no choice if there is ever to be any hope of freedom at all, but the choices he has to make and the things he has to do to keep that faint hope alive, does not rest easily on him.
The orders to shoot Galen rest particularly uneasy on his heart because he trust Jyn and he trusts Bodhi, thinks they’re telling the truth. And he, unlike Draven, saw Jedha and knows what the Death Star can do. Will do if not stopped. That it will extinguish all hope and that is something Cassian cannot live with.
And sits Bodhi Rook, ex-Imperial cargo pilot, who took a wild leap of faith because of his own conflicted heart and anguish, who sits there speaking in his quiet voice about following his heart and setting things right with himself. Do what he believe is right.
You can see it in the scene, it’s so well acted. Bodhi sits there talking to Jyn and Cassian is off in the background. The moment Bodhi says the words about “setting things right by himself” the camera shifts to focus on Cassian who has been fiddling with the space phone and we see him turn around and half look at Bodhi.
And we see the conflict on Cassian’s face, the one between his orders and his common sense telling him one thing – that Galen Erso is probably dangerous and should be removed – and his heart and conscience telling him another – that that Jyn and Bodhi are telling the truth, that Galen Erso has build a weakness into the Death Star so that it can be destroyed and something like Jedha never happen again.
And all he can hear is Bodhi’s quiet voice, slowly drowning out Draven’s.
Up on the mountain top Cassian hesitates, even when he has a clear shot. Because there is a chance that Galen is genuine and that there is hope, and Cassian doesn’t take the shot because he can’t abandon hope, Hope more than anything else, is what lives in his heart and the reason he has made all those compromises, why lives with the guilt and the pain.
So when they all return to Yavin IV and Cassian suspects that the council will turn Jyn’s request for sending a raid to Scarif down his mind is already made up. he too is going to trust what his heart is telling him, that there is still hope.
That is why he has already been walking around the base, rounding up old comrades, preparing to go on fighting, keeping that hope alive at any cost. Because of the words of a former Imperial cargo pilot with a kind heart and the courage to do what it told him.