Road rage victim was i in the wrong?

i take part responsibility fot what happend to me today. Im about 2 miles from work on a road that is a 55. 2 cars ahead of me doing 25 in a double yellow so i cant pass. i relized they were going slow as i came up on them. so i was behind the 2 cars for a few blocks and right before my turn i flipped my beams real quick just to let them know to speed up. the car closest to me slammed on his breaks reverses andd follows me in to the yard ( i work at a railyard) I park the guy gets out comes to my car. i lock the doors as he starts going off about me flashing him as he was the 2nd car in line. i tell him are you going to give **** to every guy who flashes his beams at you? some more stuff was said ii told him to leave. he then turned away then back to my car and punched it. i get out to say something and he puls a swiss freaking army knife haha. i take it from him and throw it on the tracks and my co workers escorted him out. what is wrong with people or am i the a$$hole here