Animator Window Lock is not locking controller when other GO with Animator is selected in the scene. Controller is updated when you click in the Animator UI, even though the "lock" is active.

repro:
-import attached AnimatorLock package (contains a scene with two GOs animated by a different Animator controller)
-open AnimatorLock scene
-open Animator window
-select the Camera and lock Animator window
-now select the Light (window is not updated, as expected)
-now try to click the "cam" state in the Animator window...
bug: Animator now displays Light controller, even though the window is locked.
expected result: you should be able to interact with the Camera controller even if you have the Light GO selected since the Animator window is locked on the Camera controller.

this is not a regressions and also happens in 5.4.3f1