Facelift Brake Lights

[Turbo Tony]

OK, so in a desperate attempt to get through the week before picking up my car this weekend, this is the first of a few questions I'd like to put to you all. I'll separate each topic for easier searching later.

So, almost by fluke (I did an emergency stop to let him out of a junction), I was behind an A8 D3 today and I noticed that when the brake lights came on, both the inside and outside lights came on.

In mine, only the outer lights come on with the brakes. I don't think all the LEDs will have failed in both lights, so is there a setting somewhere that turns them on or off?

Also, why do the failed LEDs not trigger a fault code?