Theory on the overactive FCTB (Front Cross Traffic Braking)

If you gently press the brake the car will slow down more than just letting go of the accelerator, but there's a very small window of braking pressure where the tail light doesn't actually come on. My theory is that the car doesn't get the signal that you're slowing down until the brake light comes on, and thinks you're just going to roll through so it stomps the brake. Just had it happen to me yesterday and I remember only lightly pressing the brake as I was only crawling up to the line waiting for cross traffic. You can try this by braking lightly and looking in the mirror near the high mount stop lamp (at night), it needs a bit more than minimum pressure before it lights up.