And? More ammo to prosecute them with.
It is not the police's job to escalate matters. Their primary objective should be to contain and dissolve peacefully where possible in these situations, both for everyone's safety (including both the protesters and the general public) and to allow services to return to normal as quickly as possible. That would make everyone's life easier.
The evidence gathering can take place while this is all going on, and prosecutions, if necessary, brought about later.
I am surprised that as railway staff you would want anything else than services being restored as quickly as possible for everyone's benefit.
Do you have any idea how much it will cost the industry (and you and me as tax-payers) if this unnecessarily turned violent and dragged on?