Mainly the problem is that Lori's dog is still a puppy and has too much energy. Also males are ususally a bit more bossy than female Westies.
I don't think that we are talking about a "bad dog", he just gets too excited and kind of looses it. While he is young it's important to get him off this habit and control too exciting situations, so that he doesn't get scared or too wind up and also that this behaviour doesn;t become usual.