If you steal a car before video cameras and detection devices were invented, and you get caught 10 years in the future with new technology, are you innocent?
If you murder somebody before DNA evidence was around, and you get caught 10 years later (and found guilty), are you innocent?
As for as I can see, the same circumstances (not as severe however) are applicable here.
EDIT: Found a post that stated that Jits gave everybody a clean slate after he implemented his cheat detection.