Belated reply - in today's Seattle Times, McKay claims he investigated complaints about the 2004 election and found no evidence of fraud. He might be lying or leaving out something, but that's what he said.
I thought that I read on the Evergreen article that McKay had claimed that the voter fraud was a state issue, not a federal issue, because ot was a state office that was in contention. The fact remains that it was a federal election.