from what ive heard on the radio, he showed the wrong ticket, and was thrown off, dont really know what happend as you cant see on that video, he could be looking in his wallet for the correct ticket when the guy threw him off.
either way the guy who threw him off had no need to do it in such a manner, if someone threw me off a train like that ide be doing more than pushing my way back on.
however i agree if he didnt have the correct ticket or a ticket then yes he should be made to get off the train, either by the conductor asking him to, or the police, no need in "big man" to get involved at all.