Both Uses of

recoil
in
Zero Day

She would employ the classic push-pull to control recoil when she fired.†
p. 52.9 *

recoil = to move backward suddenly

Definition:

to move backward suddenly (sometimes figuratively)

especially:

the backward jerk of a gun or cannon when it is fired
when a person flinches (suddenly draws back) from someone or something, as with fear, disgust, or pain
when a person is emotionally repulsed, as by disgust
when something intended to go in one direction figuratively falls back in the opposite direction; for example, a story told to hurt someone that comes back to hurt the teller