Was this act sexual abuse?

According to a rumor that I heard from many people in my school, about 25 years ago, a misbehaving boy in his 2nd grade class was forced by his father to pull down his pants in front of a mixed gender class and his female teacher and was spanked in his white briefs.  He eventually graduated with honors and never misbehaved that badly again but I remember that I heard some of his classmates, including this girl teasing him that he was spanked in his underwear and they mocked him when he cried during the spanking.