OK here's my (admittedly half-formed) thought:
I tend to see this PD35 as operating on multiple levels like most of the principle doctrines. it certainly is true from a practical point of view as written, but I don't think it is very satisfying unless it is viewed in the more abstract context of discussing the 'best life' or the "highest good."
In that context, it serves well to point out that your aren't going to be able to live the best life possible if you indeed are worried about retribution for your crimes. As the doctrine points out, once you've committed the crime you'll always wonder if it will be found out, whether you should have turned yourself in, apologized, made it good, or what. And that amount of worry is something that will always stand in the way of the at least aspirational goal of pure pleasure.
But I think it is indeed a "hard question" because Epicurean philosophy is also highly practical in realizing (in my view) that life requires pain and risk, and it's practically impossible to eliminate them. I can easily see the prudent Epicurean saying that just like the rest of life, it's a practical question of whether you should violate the seat belt law for a ten minute drive to the store, or violate the speed limit, or do any of a numberless type of crime where you might rationally deem the risk of punishment to be worth committing the crime.
So I do tend to see this one as I tend to see many of them - more of a logical observation that is good for debating the greatest good and the issues of crime and punishment in a godless universe. I do believe it's a true observation, but it's also a true observation in the Epicurean scheme that everyone is going to determine for themselves what degree of hardship and risk they want to undertake in order to gain the pleasures they want.
Now having said all that, I wonder if in listening to the podcast you heard anything about Plato's views of the ring myth that might give us subtleties on how Epicurus' viewpoint was a response?