Good question.
Perhaps "mom" is too consumed with grief over the loss of her son to be out in front displaying the same diarrhea mouth as her husband...and rightfully so. The poor woman.
I feel so sorry for her. To lose her baby (they never really stop being our babies, do they?!) and having her hubby desecrate her son's memory in such a manner. He's allowed his viewpoint, but he's behaving shamefully.