Thats isnt quite accurate. They didnt press charges because all they had was a grainy video of him drawing and they could not prove it was concealed. It has nothing to do with wether or not you coudl see part of it, it just cast reasonable doubt as they have to prove he concealed it unless he admitted which he didnt thank god.
Wasn't there an incident in Omaha in the last year or two where a guy shot a robber in a gas station (kid with a shotgun) and didn't have a CCW. However, somebody said they could see some portion of the gun and they considered it open carry and didn't press charges.