Bike Anti-Porn - When Things Go Wrong

quite right, internal gears inside the bottom bracket, has been around for a bit, it also mean you can ride it as a fixed wheel having it in the bottom bracket instead of the hubs (as far as I remember).

Looks like a Schlumpf Speed-Drive, which I think has no freewheel system (unlike Truvativ Hammersmith[sic]), but the Schlumpf manual says

Fixed-gear bikes
The speed-drive mechanism is not designed to withstand high-torque pedal-
ing in both directions.

Assuming there is no freewheel, I'm guessing a skid would rip the BB out of the frame because the torque of the planetary gearbox is resisted only by a serrated threadless BB, not a solid connection like the Truvativ.