My dad Bryce Bayer (Kodak Rochester) worked closely with Phil Powell (Kodak England) throughout this period. I don't know what Phil Powell specifically contributed to the 'Bayer filter'. I do know that my dad would have liked to have shared credit for all related work on digital photography, but that Kodak Rochester did not want to share credit with Kodak England. I'm also a mathematician, and I see how the details may be beside the point: When one grows a tree together, one wants to view all fruit of the tree as shared.