You don't get to call it "stepping out of line" if there are no consequences for doing so. See for example how the My Lai Massacre was handled[1]. The pattern continues when it comes to shooting down an airliner[2], an airstrike on a hospital[3] and many more cases.
If no-one ever gets more than a stern talking to, then clearly there is no line. These actions are as close to adhering to policy as you can get without saying it outright.
[1] https://en.wikipedia.org/wiki/My_Lai_massacre#Investigation_...
[2] https://en.wikipedia.org/wiki/Iran_Air_Flight_655 (there is even less to see about the aftermath here: everyone got a medal)
[3] https://en.wikipedia.org/wiki/Kunduz_hospital_airstrike (this time someone was disciplined)