At night both tail lamps are lit.
Generally it’s best to design vehicle signaling with an assumption that situations are not ideal, just in case.
If one of the two tail lights and/or a brake light(s) is/are out then the situation will only be worse.
I'd short Cooper stock were I an investor. This will cost them a pretty penny.
Gawd, I can't imagine what a self-driving car would see when it is following a Mini down a foggy British roadway. Perhaps someone could model it?
It's the US spec that seems incredibly poorly thought out.