Why? Shaw wasn't there. All he has is after action reports, and a lot of crises, since, you know, they are the main characters of a show. Except Shaw doesn't know that.
Laughable maybe from our perspective but is Shaw us?
Hmmm, perhaps Shaw learned of Picard's adventures from a biased source (maybe from someone who didn't like Picard so they tried their best to make him look bad)?