Here's some free legal advice: if you see anything going down, get the fuck out of there. Don't try to be a hero, don't try to be a good Samaritan, don't offer to be a witness.  Trying to be a hero can get you hurt, or, if you hurt them, can get you sued. Offering first aid can get you sued, if you fuck it up. Offering to be a witness just means you'll have to go testify at a deposition or at a trial. Nobody has time for any of that shit.  The sad truth is that our society is so litigious that it is best just to mind your own business.