David Grace QC, representing the Eagles, entered a guilty plea early in the two- hour hearing at Etihad Stadium.
He then went about presenting a case for leniency that included a long list of character references and a contrite Gaff giving evidence that he didn't mean to hit Brayshaw in the head.
Jeff Gleeson QC, representing the AFL, described the incident as a "historically significant event" and recommended a suspension between eight and 12 matches.
