Here's the issue. Point totals update real time apparently. But rankings only updates once a day (at 1 am for me on the east coast of the United States).
Because of this, at the end of the contests, your position on the leaderboard does not display correctly until well after the contest ends (at 1 am eastern). The system will pay you out the correct ranking rewards (I have compared this) for your point total, regardless of where the leaderboard says you are at.
That's where the confusion comes to play. People are getting their rewards based on their point total at the end of the contest, but believe that they have been shorted in their efforts because the leaderboards rank % does not reflect the position at the end.
The short term fix for this might be as simple as going into the code, and changing the time of day that the leaderboard refreshes to an half to a full hour before the contests end until you guys figure out how to make it update real time.