The first picture is typical rear inner wear of a RFT, no alignment issues, just normal wear with BMW settings, and running a higher than door placard pressure setting. But the beginnings of the grooved wear.
This is typical of the wear we do see on the rear, sport settings and running low pressure, mean this is quite common.
This issue is discussed quite often here in the UK. A well respected tire and suspension specialist, WIM (Wheels in Motion) come across this quite often.
A combination of camber, tyre stiffness and pressure, allow extreme distortion around the tyre junction of wall and crown, marked on the drawing (A). Once the structural tread 'bridge' begins the wear the tire is weakened, distorts even more, and the wear accelerates.
The stiffened sidewall cannot distort enough to share the load, so the load is very local to the junction.
HighlandPete