I was wandering around the Web, learning, this morning and I found this. Note to myself to pick it up, sooner than later.
Here: ... she said this only to her brother, who was also Moshe’s brother. Clearly Aharon was not going to spread this around; it was to stay between them. Despite the local nature of this infraction it was still inexcusable.
(The whole entry is really good. I recommend checking it out.)