I recently completed a First Responder course (in order to be a ski patrol) and that was one of the points the instructer made. First responsibility is to keep him alive, saving his back, neck etc comes next. As instructor said though, it is often a tough call -- do you want to risk keeping someone alive as a vegatable?
In retrospect, it seems like they maybe should have immediately redflagged the race, and tried to revive him there on the track, rather than moving him to the ambulence first. I wasn't there, and I am not the expert in any case, so I won't try to second guess.
There have been past complaints about the way the Japanese marshalls handled similar situations in the past though. Many of the racers feel that, unlike American or European crews, they put keeping the racing going with minimal disruption ahead of rider/driver safety.