Rananim
The pilots mindset was quite rightly to use everything at his disposal(spoilers/one rev/max braking).
Not quite true - MED Autobrake was selected, if PF had intended to use max braking I reckon he would have applied full pedal deflection very soon after touchdown.
The designers give him the one retardation device that commits him to a landing before making him cancel all fwd thrust and fulfill the condition that give him spoilers and ab.
Here's a contrary thought .... Perhaps it is safer, with one T/R Inop, not to select reverse thrust at all, but simply retard both T/L to Fwd Idle? Discuss.
Tyro