I worked as a street reporter on major metro papers for more than twenty years, and did a lot of police reporting. In the past couple of decades I have on occasion given speeches to police groups, and have said without much objection that I thought perhaps a third of cops shouldn't be on the street. They have issues with what they see as their own authority, they may be bigots, they are poorly trained, they are not bright enough to be out there, they are burned out, they are very often frightened. When you actually deal with cops on a daily basis, and hear some of the sh*t that some of them actually believe, there is good reason to be nervous around them. I'm a tall white-haired white guy and I drive expensive cars but when I'm stopped by the cops (in the past I've been a little heavy on the gas pedal) I keep my hands on top of the steering wheel until they ask me for my driver's license, and then I say, "It's in my wallet" so they know what I'm doing when I go after it. When you are stopped by a cop, you are in serious danger. And when the cop realizes he's dealing with somebody who poses no danger, they often show signs of relief: even a routine traffic stop heavily stresses them.
Give all of that, I have to say in this instance that the tripod could have been mistaken for a gun at a glance -- especially a high tech black rifle of the kind used in recent massacres. And a cop might believe he has only a second or two to decide what to do. A more famous version of this incident took place in Iraq where a well-known television (video) photographer raced up to a combat scene, jumped out of his car with a large TV camera, pointed it at a helicopter, and was quickly killed by a helicopter door gunner (IIRC). The TV camera didn't look exactly like, but looked somewhat like, an RPG launcher. The door gunner felt he had about 1 second to make the call. The photographer was incredibly stupid to do what he did, and he died for it.
I often get tired of these news stories about how awful the cops are when people shot by cops were actually fleeing after a crime, they have something in their hands, and it's dark. The cops are scared, too. God knows enough of them killed. So don't run. You're running because you think they are going to put you in jail? Then go to jail -- its better than getting killed. Obviously, young black men are in more danger from the cops than tall white-haired white guys -- it goes back to the bigotry, the poor training, the fear, the burn-out -- but the rule still stands: give up. Hands over your head, nothing in them.
We're living in a time of increasing international and domestic terrorism, and the cops are getting it from all directions -- if they over-react, they're vilified. If they under-react, they're vilified. If they react properly, but something goes wrong, they're vilified. So they're on edge, all the time. I can only repeat was the OP said: Be careful out there.