Changing a key binding in game through the Settings > Controls window to a key that is already bound to another control results in a confirmation/warning dialogue with “Apply Changes” as both options. This appears to only be a issue with the text being incorrect as the orange button applies changes as expected and the blue button discards them.
As a side note, in the other settings windows (General/Video), the “Apply Changes”/orange confirmation button appears on the right, with the “Set Defaults”/blue cancel button appearing on the left. This is contrary to the Controls Settings window and many of the other confirmation dialogues in the game (Restart Map/Reroll Map etc.) that have the orange confirmation button on the left with the blue cancel button on the right. Not a problem as such, but having the order of the buttons consistent within the UI may help with the user experience.