Audrey's question reminded me... Would you have said anything here?

We were at the park a few weeks ago, pushing our daughter on the swing. A dad and his son came up and he was pushing his son on the nearby swing, I guess. I didn't really notice until he started screaming in the kid's face. I asked my daughter's dad what had happened and he said the chid let go while his dad pushed him and so he fell forwards and got hurt. But the dad was seriously screaming angrily directly into this hurt child's face, "I told you not to let go! Are you happy now?! Now ya got hurt! Look at me. You happy now?..." on and on and on. I didn't see the child fall and I never saw or heard the dad check on him or apologize. My only thought to even somewhat excuse this was the dad was embarrassed he hurt his kid?? I don't know. He just yelled at him for several minutes and then eventually made him leave the park in tears, screaming at him the whole time. The length of time it continued made everyone uncomfortable but no one said anything. Would you have?