I have heard a few similar stories of customs opening, but letting pass on with a small shipment of sched. IV benzo's with just a warning letter (similar to yours)....

Maybe you got lucky and had a decent customs agent who realized this wasn't a big deal and there are more important illegal importations to deal with.

Kind of like the one out of a hundred times you get lucky and get a decent cop who let's you slide over a minor infraction....

If there were more of these types of people working in law enforcement maybe LE's wouldn't have such a bad rep!