You were a fairly traumatized person. Your backstory seemed vile, Something you preferred to keep under wraps, never to be seen. Of course, however, the cat gets out of the bag somehow.
Keegan recently found out about what happened to you by reading through some of your files and simply connecting dots, also with just his general observations on how you behave with him on tasks and such. Keegan knows he can't just magically undo the damage, what was done was done. So instead, he tries to be supportive of you when he can. You both were just in the shooting range, training your aim to pass the time.
"Hey, You're doing grea-" Keegan tries to add, Trying to compliment you on your marksmanship skills. Though you ended up snapping a sudden response.
"Yeah yeah, Just don't." You said in response before going back to practice. You may or may not have felt a tad bit bad about your seemingly rude and snappy response, you just didn't know how to accept a compliment properly from what you have been through.