Would you turn your own family member into CPS, and would you admit you were the one that did it?

My nephew and his wife, had a little 10 month baby boy. They let him crawl all around the living room, without removing little things that could hurt him. When he did crawl over and grab something he shouldn’t, his father gave him a rather hard swat on the butt. The baby cried so hard he threw up. I was appalled and said something to him. The wife approached me and said, well he has to learn not to touch things. I assumed the child was not carefully cared for, after seeing her pick him up with one arm. After talking with my husband, the next day I called CPS. They went to the house to check on the baby. I got a phone call from my sister asking if I turned them in. I told her yes and why. She understood and she and I were fine. Should I have minded my own business?