I can't believe AirBus guys use the FMS FD guidance for vertical path below 500'.
RAT_5 you may be thinking about final approach guidance, but this type of procedure isn't designed for that. Indeed the FMS Bridge procedure is meant to bring you to about <4nm from the runway threshold at 1,200ft.
But the procedure starts at ARCHI which is 25nm out at 8000ft and has many "stair-step" altitude restrictions to remain within the SFO Class B. Due to high workload during parallel approaches, pilots have been known to bust these restrictions (or conversely "dive and drive" often with high descent rates). So this is where RNAV automation can help out.
The entire procedure is still designed to be visual and you have to be clear of clouds throughout. Which means that at night the pilots should have picked up the correct runway environment from a longs ways out.