You could Start and End your trip on an AGR Reward Ticket in the same Zone no matter how far you traveled as long as it was not more than 2 Zones and there was no layovers.What were the
What was the'Loophole trip'?
For Example: Austin to LA to Galesburg to Springfield to Austin(4 LD Trains and 1 Thruway Van)and it only counted as a 2 Zone Trip( 20,000 Points for Roomettes for 1 or 2) since you changed from Zone 2 to 3 @ El Paso and back to Zone 1 @ Albuqurque.
Now, with AGR Rewards based on Fares, it would be around 80-125,000 Points depending on the Buckets and Number of passengers.