Oh please. I heard Michelle say something about how big the horses were , obviously in response to one of her daughter's comments and it appeared they were a little worried about Bo. So what if they did not pet the horses. I don't like to approach horses in harness either: there's too much to get smooshed by. Does everything have to be so hateful? Shame on you. It is Christmas.
A conclusion is the place where you got tired of thinking. (Steven Wright)
Perhaps she was advised not to touch the horses? Like service dogs who are working you aren't supposed to touch or pet them either.
So just perhaps she was advised not to touch them. The one seemed a bit restless and had troubles standing still. So for her safety and the safety of everyone no one was to touch the horses or the wagon as they gave that a wide girth as well.