Bloody brilliant...I love stories like this! Well done that man!!! You should have followed through and spoke to the store manager - retail is such a fickle business they would have probably given him a written warning for that. The very fact that a customer felt the need to stand up for the 'poor, helpless girl' would do the 'massive, bald, horrible' manager no favours....
I once bollocked a woman for hitting her kid round the face several times. I couldn't actually believe people were just standing there letting it happen! Believe me it wasn't just a smack (and I believe in smacking by the way), she was proper clouting this 4 year old round the face. I told her if she did it again, I'd shout for the [Transport] Police. Needless to say, she didn't do it again.