Surely everyone who has a heart attack suffers from permanent heart muscle damage,
Not necessarily, and the degree of damage can vary very widely depending on how quickly they get proper treatment.
it would probably have been at least an hour before he got specialist medical help. Would that have made a difference to his outcome?
Its quite possible. Treatment given 1 or 2 hours after a heart attack may well save heart tissue which would otherwise have died 6 or 8 hours later.