Hennes best game as a pro was 2 years ago against Jacksonville. He was poised in the pocket, made all the throws, made all the reads, and spent a lot of the game in the shotgun. It have never been that Henne can't do it! It has been that Henne hasn't done it consistently!
Are you really trying to claim that about a game where Henne didn't put the ball in the end zone once, only scored 14 points, and where Henne took a game whose outcome wasn't really in doubt and made it that way when he threw a costly interception that let Jacksonville back in the game, was his best game as a pro?
That game is everything that has ever been wrong with Henne. Even when he seemingly brings his best game and makes "all the throws" most of the game, he takes 220 passing yards and a 140 yard rushing effort but can't put more than 14 points on the board (contributing none of the scores himself) and nearly loses the game for his entire offense by throwing a pick.