I'm really bad at answering these kinda threads,My husband gets mad i stick up for the dogs more than him,Ok a whistle.They are loud,probably hurt his ears and he was saying stop,We all know how young kids are right,My Rb Bandit,when i had him in obedience,I was standing watching the instructor with Bandit,There was 2 kids behind me the little boy was (shooting those plastic bo and arrows at this little girl)She was screaming Bloody Murder)Bandit lunged at him never touched the child,But it was like he was saying STOP IT!

Im sure Rupert will be fine,I have never seen a vicious chocolate Lab,He most likely got irrated,Im sorry about your brother how old is he?