The vehicles basically can't deal with the RADAR returns from the curved wall ahead of you, so they either start ignoring things that they shouldn't, or you get phantom braking. RADAR and LIDAR are both problematic unless you have a proper 3D concept of your expected path, which Tesla's AP apparently does not (though the new smart summon is apparently heading in that direction).
So the complete failure to brake while in a curve doesn't surprise me in the least. The straight stretches, however, are disconcerting. Then again, this could also be tester error, e.g. if the driver was pushing the gas pedal and thus inadvertently disabled automatic braking.
