We didn't think a one lap penalty existed either. Unfortunately, we didn't capture it on video.. and if we could replicate it and rule it out as either a bug or error we would just manually change the standings.
All I know is that on the standings board after I finished I immediately starting dropping down spots as my competitors finished, and next to my name it in the area where a "3-second penalty" for either cutting corners or collisions would be it just said "Lap" and dropped me into last place.