Oh wow, that sounds terrifying! And the lady sounds like a complete idiot!
How is Kingston doing? I think I would take him to the vet for a checkover just in case. It wouldn't take much for a big dog to cause internal injuries or damage his spine. Hope you and he are ok!
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He is your friend, your partner, your defender, your dog. You are his life, his love, his leader. He will be yours, faithful and true, to the last beat of his heart. You owe it to him to be worthy of such devotion. -- Author Unknown