I won't comment on the technical seriousness or not of this incident but for JAL it signals quite a lot of potential trouble from the Japanese authorities and travelling public.
This is another in a longish line of mostly non-events with JAL that has been leaped on by the Japanese regulators and media. JAL were issued a formal warning about it's safety and operational procedures last year (March I think) and following this they have been given a second warning (Jan 9th). Two strikes out of 3! Any more repetitions and the Ministry could impose serious sanctions on JAL.
Public confidence in JAL has already been affected and load factors are down I believe, especially on domestic routes where ANA offer an alternative. As usual, the media have been hunting down any similar events with ANA as well, so they have not been immune from criticism too.
PTH (currently located in Japan)