The impact of the refs is really overblown. They do fine most of the time. Sometimes they blow a call or miss something. Those times suck, and sometimes they really do impact the outcome, but I don't believe it is intentional and often those calls are closer than a lot of biased fans want to admit. And sometimes the fans just don't know the actual rules and are calling for flags on perfectly legal plays (such as holding by the offensive line in certain situations).
All that being said, I don't think the refs actually try to help the Chiefs, at least not consciously. It is impossible to eliminate bias, though, and that can creep in from time to time. But there is no larger conspiracy.