Ok, we all use the Mahjong auto. Every puzzle we finish with it, we are left with 00:30-01:30 on our timer. That is sure way on knowing we are using an auto. But I have a idea for a helper. Just before the auto finishes the puzzle, the helper will add time by clicking the "Show All" or "Hint" buttons until it reaches your time recommendation (ex. at least 02:00). That way the puzzle will be finished the same way and we will not get caught.
There is already a helper in the downloads section that will do that. Look under Mayhem's helpers. ;)