The shape of the Object in the (R) Hand of the man wearing the Light Colored Shirt in No Way resembles any kind of hat imaginable. Whatever he is Holding in his (R) hand is Uniformly Cylindrical from its' Top all the way down to its' Bottom. This is Not the same man we are seeing on the Altgens Photo who is wearing a Light colored hat contrasted by a DARK/WIDE Band.
It's amazing how flexible you are, first of all the man in the white shirt was levitating then when it was pointed out that the man was sitting against a wall above the people lining the street, out comes the next "observation". Rinse wash repeat.
The man in both photos is heavy set, appears old, is wearing a white shirt, is above the people lining the street, is sitting towards the end of the wall and has nobody sitting to his left, which can only lead to the man being the same person and if your best evidence is he ain't wearing a hat then you got nothing.
Even if the object isn't his hat and since you are reduced to speculating, it was lunch time and it could indeed be a stein of beer which he is raising with his right hand and as the President is driving by the older honorable gentleman simply showed respect by removing his hat with his left hand. Now, isn't this scenario more logical than Altgens taking his photo to the alteration lab and having it checked and for some reason they new what to alter, did it real good and did it real quick, then immediately the image was wired across America for Newspapers that very same day, are you sure this is what you think happened?
JohnM