One notes the following:
-It is apparent that the speed was high near the usual turn-off with high reverse on No.1 showing.
-It is thought a go-around was being attempted. There cannot have been much runway left from the point where of usual turn-off, therefore not much time to allow for transit of No.1 from high reverse to reverse idle to forward idle to power up.
-The evidence shows there was a marked swing left off the runway. If indeed a go-around from a short runway landing was being attempted, it seems highly possible only high power from one engine (the right) was likely to be available whilst No.1 would still be transiting or increasing power. At the sub-V1 speed at the time, this would be an undoubtedly doomed scenario with an uncontrollable swing.
I think the maintenance state of the aircraft is totally irrelevant anyway to the cause of this accident. Even with both reversers functioning, it is highly unlikely that a go-around from landing deep on a shortish runway and in reverse power will be a successful alternative.