I'll speculate:
He had a crash and a rather sporty ride on an ejection seat.
His rear seater, the chap he was responsible for, perished.
His job requires 100% concentration.
Perhaps, just perhaps, Red 3 is a human being and hacking around in a diamond nine is not something he should be doing right now, for a plethora of sensible reasons.
Short version - FFS, give the system/guy a break.