Highway should have been closed, everyone detoured or stopped. There should have been no traffic for them to interact with.
They say he illegally enter the interstate?????? Ever drive a road tractor pulling a 45 ft trailer. One cop car could have blocked an on ramp keeping him from driving around and entering the interstate. The cops F-ed up. Either he entered the interstate at a clear on ramp or had been driving on it for a while.
They say he was blowing his horn. He managed to stop the rig. This was at a curve. If he had locked the brakes, he could have jack-knived, rolling the trailer.
They screwed up by not having the interstate closed.