Losing the rear under heavy braking at speed while you car is turning is simply a more severe form of trail brake oversteer, which is a more severe form of trail throttle oversteer; Racing, in part, is nothing more than a game of managing weight transfer to maximize available traction.
Macau is a very challenging circuit not just for drivers, but is a nightmare for engineers to have the car set up. Not only is it extremely bumpy, so the engineers will have to make a compromise between bottoming out the car and suspension compliance. The corner where that accident is at is call the “Maridian”, which is the fastest corner of the circuit, cars (especially open wheeler) are usually set up to have just enough down force to take that corner flat out. If you don’t you will get pass everyone behind you once you reach the real first corner of the circuit “Lisboa”, where you will see people going 3 or even 4 wide jockeying to take the corner first. Once you are on the mountain section, passing is basically impossible until after you exit the hairpin at “Fisherman” and “Reservoir”.