Why is Pro Stock Dodge down on horsepower ?

It seems it was right after they were caught with NOS in the oil pan. The break in might have been a cover up because they gave up soon after.
Were they actually caught with nitrous in the pan? I remember Jerry Eckman (Pennzoil Pontiac) getting busted when a bottle in the pan exploded in the pits. Blew the pan apart! I think the NHRA banned him for life IIRC.