Not 100% sure but think it may have happenned to Bonnie in the 1st series.
You're correct - Bonnie and Matt topped the leaderboard before being designated to the skate off against Kelly and Todd.
The following week they came joint second and found themselves fighting for survival against David and Pam. The judges ruled in their favour.
They fell at the penultimate hurdle when despite taking the judges vote public opinion decreed otherwise and they were relegated to 3rd place behind Gaynor and Stefan.
Statistics can be interpreted in many ways - usually to suit the opinion of the statistician. In the words of Disraeli there are lies, damned lies and statistics.