If cycling in Japan is anything like it is in the rest of the western world, this "statistic" must be total hogwash and a very bad case of victim blaming. Reminds me of a similar situation in Belgium where the Antwerp police initiated a campaign based on the statistic that 1 in 2 traffic accidents in the city were caused by cyclists either riding on the sidewalk or in the wrong direction in a bicycle lane. This proved nonsense (both infractions weren't even in the top 10): it was a politically motivated manipulation to whip up some anti bicycle sentiment in election times. Quickly debunked and causing the Antwerp police to eat (a little) crow.