AITA: I honked at a pedestrian

Today I had a man cuss me out. I was coming around a curve (not a blind curve, but it is a curve many people in the area speed around), and there was a man with his dog on the sidewalk. He did not check the road at all before stepping into the road and if he had, he would have clearly seen me coming and that he didn't really have time to cross (I was going under the speed limit, as people often cross here even though it is not a crosswalk).

I had to come to a complete stop to avoid hitting him. I'm confident if I had been one of the many drivers who isn't attentive, was on a phone, or speeding, he and his dog would have been hit. As I came to a stop ~50 feet back from him, I gave a short tap on my horn, because he had shown ZERO indication that he even saw my car, and the entire time he crossed the road he did not check either traffic lane.

The man immediately turned on my car, shaking his hands and coming right up to my grill and screaming. I was pretty shocked because all I had wanted to do was let him know, "hey, you didn't check the road before crossing and a car was here, that could have been dangerous!" I opened my window and could hear he was yelling that pedestrians have right of way (obviously.... but it doesn't mean it is safe for you to cross a road without ensuring it is safe for yourself and your dog). I tried telling him I saw he didn't look before he crossed and there are multiple crosswalks in the area, but he kept yelling over me. I ended up backing up and going around him because he would not move.

I can understand honking might have been seen as aggressive but I tried to make it a light tap, I just wanted to get his attention and make sure he realized he had chosen to cross the street at an unsafe time. Should I have just not done anything?