AAHH! so many things to say.  First of all, what was your friend doing walking on the graveyard at night?  Also is this one of those graveyards that have a gate that closes at night? If so then he souldn't have been in there in the first place (don't missinterpret me I just follow SOME rules).  Second, Who were the ones shooting? Gravekeepes or "normal" folks?  If they are security they should have first inform authorities and then assess the situation (without shooting ofcourse)  Don't think I am one for authorities, but if it is banned to enter the graveyard at night and if your friend sneaked in, then he should have followed that one rule (Again don't get me wrong, this is a What If analysis I do not know all the details in order to give MY full opinion and jurisdiction regarding this  ) Third, What's up with the shooting?! (hope your friend is allright) Are those people morons.  There should not have been any reason for shooting unless they have been threaten.  And specially they should NOT under any circunstance have threatened you with the gun.  I think you should report this whole gun threatening, but you should do so with proper attire in order to get authorities under your control (make them believe your words and the authorites become puppetts).  Fourth, WTF? people shooting? are they     R tards or something? Fking R tards.  (I know I am repeating myself with third and fourth.  But seriously Fking R tards.  No offense to the people who actually have a health condition, and sorry for familiarising them with the morons who shoot at graveyards at night).  

As to what I would do, Heck idk. It has to be me under the situation in order to know, REALLY know, what I would do.  It's always easy to say something when one is not on the spotlight of things.  Kuddos to you for being brave and face them, but i'd be careful if i were u.  There really are some stupid-idiotic-ignorant-morons out there.