> What I want to know is.
>  Are train staff insured against asault and injury?

No idea... but insurance companies might have clauses in the small print
when these things occur.
They will pay when an employee falls down the staircase and breaks his leg,
but not if you push him (given the fact that your are caught). Maybe they'll
have to pay if no perpetrator can be found.
BTW, don't count too much on Japanese insurance companies. They always try
to weasel out. And if you can't speak Japanese, you are more likely to get
milked!
The worst scenario is when you are involved in a traffic accident while 100%
innocent and both parties own policies of the same insurance company. The
company will always try to "distribute" guild so that both will need to pay
higher premiums during the next term. I had to threaten with a lawyer... and
after in-house consulting they took a step back.

Sigi