A recall is great, it is the right thing to do by HF, and shows that they do care about the quality of their products.
The bigger issue, I think, is that jack stands by nature are dangerous. I would wager that incorrect use of the jackstand is likely behind many of the failures. When I say incorrect use, I mean uneven loading, shaking or moving of the vehicle, or using them on an uneven surface. Add to this that the average HF jack stand user is not a professional car mechanic and uses them seldomly with minimal training.
So many variables that can make the vehicle fall. Always place a secondary safety under any car that is lifted in the air. Even then, shake the vehicle before getting under it to check for movement.
Pinned or not, a shifting weight balance can occur on any lifting mechanism.