Have you guy's seen this Anti-Hunting video, this could be you....

Where does it show that he is trespassing or illegally hunting or doing it in an unsafe manner?

I"m not taking sides on this, just answering your question. If he is hunting/shooting an upland game animal, which a tree squirrel is in some states, it can be illegal to stalk game in a vehicle, which he is clearly doing. Also, if the road is not a private road, he cannot shoot within 150 yards of the road. 
 
Don't see where you are answering my question. Never heard of a squirrel being classified as upland game. Besides that, he was hunting dove, not squirrel. Never heard of it being illegal to spot game with your gun scope from a vehicle as long as your not actually shooting said game from the vehicle which he did not do in the video. Cannot shoot within 150 yards of a road??? Are you just assuming what state he is in? In my state of Maryland the law says nothing about any minimum distance from a road, just that you cannot shoot on, from or across any public road. You are just assuming just like the other commenters. The video and text don't give enough information to prove any wrongdoing.
 
Rego number visible on the vehicle but un-readable to my eyes, no real shot of his target/s, dead bird doesn't mean he shot it. At 1.25sec look at the bush lighting change on right bottom of screen, note shadow of the tree on the road, when vehicle arrives shadow is longer towards the camera than when the vehicle leaves. These are continuity errors in the production process.