can an owner even do such a thing?
About the only thing that an owner could do...is tell the coach to bench the guy...lessening his value...and helping the team make a decision at the end of the year to let the guy go. In this scenario...no team will touch the guy, and you slowly filter out the ‘actors’.
Don't you think every owner in the NFL would ban the top five players on the opposing team for any reason if they could get away with it?
Can an employer walk an employee off the premises? Yes.
I would think as the sponsor of the event, they would be able to eject anyone they deem to be making trouble.
Even if it isn’t legal, eject the mook and let the other team fight it out in court months or years later.