Complex sentence: He maintained that the contest was rigged until the day he died, and never said he thought that he should have won, but that Arnold shouldn't have, though he eventually got on good terms with Schwarzenegger.
Split into simpler sentences: He maintained that the contest was rigged until the day he died. While he never said he thought that he should have won, he maintained that Arnold should not have, though he eventually got on good terms with Schwarzenegger.