You need to see what planets were were , I mean in transit during the time this scandal become public to do an analysis as to any he did not get go to jail. What was the position of Rahu and Ketu at that time. As can be seen from his chart Rahu is exalted in the 9th house that is bhagya stan. By the way just for your knowledge you are correct that 12th house is for jail, but a strong 12th house as in his case can be one reason why he did not go to jail. See as Vedic astrology the 6th house is for debt and enemies, therefore a strong 6th house indicates that the person will take dbt but will remove it. Similarly 8th house which is the most malefic house an it is the house of longevity. A strong 8th house indicates long life. Likewise a strong 12th house indicates less chances of going to jail.
Blessings,
Navneet Khanna
Astrologer