Can edit Read-Only FBX clip in dopesheet in this specific workflow.
This should not be possible.

repo:
-drop attached fbx into project
-expand fbx and select "Take 001" clip
-open the AW and select keys in the Dopesheet (without opening the Curves tab)
Bug: You can move/edit the keys
-click the Curves tab and try to edit the keys... locked as expected.
-click the Dopesheet tab and try to edit the keys... locked as expected.
note: to repro a second time, select another clip (update the AW), then re-select the fbx clip.