This is what made me think it was Chub that needed some practice.Boss get on with dogs.
But Boss's behaviour is less than ideal too. Frosty wouldn't do what either of them did.
And I wouldn't leave Boss alone with children or small dogs or puppies based on what has been said so far. Not sure about the other dog Turbo.
It does seem a little like the things you read in the paper "my dog gets along with everybody - he's never done anything like this before"...
But that would apply to both dogs.