There are several things not in dispute. Williams took money be part of the dump. He admitted as much, not only before the grand jury, but on several other occasions. He hit well during the series, the highest of all regular position players on either team, and while a look at his fielding statistics doesn't show any problems, several knowledgeable folks watching the Series, notably sports writers Ring Lardner and Hughie Fullerton, observed that he overthrew cut-off men, threw behind runners and seemed to shortleg some balls hit to his field.
What is in dispute is Jackson's motivation. He does not appear to have been a fundamentally corrupt man, as Gandil and Risberg clearly were, and his claim that he was bullied or coerced into the fix by Risberg has some credibilty. It is offset by the fact that he insisted on getting paid up front, and is one of the four among the eight conspirators that saw any significant cash.
I have a lot of sympathy for Jackson, in fact for anyone who played for the arch-tyrant Charles Comiskey, but that does not expiate his admitted guilt. The decision to kick him out of baseball was the correct one, and while I think that he finished serving his lifetime sentence on the day he died and should be allowed into the Hall of Fame now (while Comiskey gets kicked out, if there's any justice) his ban was entirely justified.
