I don't particularly care about the Heisman and never have, so I didn't particularly care that much when Manning lost it in 1997. Individual awards in team sports are vaguely interesting, I guess, but I can't imagine holding anyone other than the athlete himself holding a grudge about it for a decade.
That said -- it was pretty instructive to me to watch some of the 1997 Tennessee/Arkansas game on ESPN Classic last year. That game was played midway through November, and the announcers spent a fair amount of time speculating about Manning, and the Heisman, and how basically they thought he was going to win it by default. The consensus at the time seemed to be "Who else can you give it to?" The announcers listed a couple of other guys -- and I was pretty astonished to hear that Charles Woodson's name didn't even come up. Keep in mind that this was only about three weeks before the award would have been handed out, and Woodson didn't even get mentioned on these announcers' short list.
It seems pretty clear in retrospect that the voters were never very thrilled with Manning to begin with, and he became the overwhelming favorite mostly by default. The fact that they were so quick to give the award instead to a guy who had basically three great games at the end of the year doesn't say as much about Woodson or ESPN as much as it does about how blah the voters were about Manning to begin with.