With regards to Belichick, its funny because these comments by Belichick are out of character for him, very seldom will he speak to the press with anything personal. His comments tell me that there was far more of a rift between he and welker than was let go to the public. Welker's departure wasn't a dispute over money or contract length it was simply bad blood between the two.
In the end I think Welker got the best of him and Belichick is still severely pissed off about it.