I did that to my dog a few weeks ago. Went to drop kick a tennis ball for her down the beach and as I swung at it, she put her mush in there to grab it. She cried like a baby and I felt awful No lasting damage thankfully .
I wouldn't be so specific as to state a kid has to be on the beach to deserve it. Beach, field, asleep in bed, school, playground, at the doctor's office for a painful head... It's all game.