I do not see any semblance of wrong doing. There are some people that Lord help me. They seem to be looking for someone or something to offend them.
I have had times when at an outdoor rifle range that people were shooting when I was firing off some of the big boomers that only get fired on very rare occasions. Two have muzle brakes on them that amplify thier repoer greatly. I always take several extra pairs of ear plugs incase someone is shooting when I fire them. I will offer the ear plugs so people can double up on hearing protection. One guy refused, and I think he dropped his rifle while casing it when I fired off a 7.62x61 S&H from my grampa's old custom built rifle with the muzle brake. It sounds like a howitzer firing. He was demanding a refund, saying that I was firing off a .50 BMG the range manager and I are good friends I showed him the rifle when I arrived. He then came to make sure it was not what the offended man said it was. He then shot it, and laughed.
No matter how many times you do it and nothing happens it only takes something going wrong one time to kill you.