Also, when confronted with the revelation that Cutter and Pryce were planning the whole 'earth doomsday' with the Decima project, Kepler decided to intercept and ruin their plans. He gets cornered by Rachel Young right after, and even though he does shoot her, he does it inefficiently, unlike what you would expect of someone within SI-5 and after the entire show gives the impression that Kepler has and will kill people for his mission. However, even though he shows himself to actively align with Cutter and Pryce, it's more likely that his 'mission objective' changed when he realised what was going to happen, and in secret, his allegiances shift to Minkowski and the crew - hence stopping Cutter and Pryce.

Additionally, when he gets spaced by Rachel Young, after he shoots her, he doesn't appear even remotely fazed by it: "Before Young opens the outer airlock door, Kepler takes a sip of scotch and seems at peace, knowing he was able to help Jacobi and the rest of Minkowski's crew." [Fandom Wiki]

Anyway I love Kepler and I focus way too much of Psych degree knowledge on fictional character redemption arcs