"It only matters if you get caught."
True with any violation of the law. But the trouble with even those "minor" kinds of violations, it only takes one zealous ATF agent, eager for promotion, and a U.S. Attorney who hates gunowners and wants to impress his boss, and some poor slob ends up in jail for years. Every one of those minor "crimes" is a federal felony and folks can not only go to prison but lose the right to own any gun forever.
That was exactly my point. If you want to play the odds, be prepared to pay the consequences.