Was the inadvertant Safariland dump carried in the over the belt (split 6) type carrier? I think I've had one release when carried in that type. If one isnt familiar with them, the loader is carried with the belt through the middle of the loader. It makes it much more compact to carry. I use them, but am aware of the possibilty of a release if the carrier is pushed down hard from above. The belt apparently pushed the release button hard enough to activate it.
I've had some Safarilands not release cleanly on several occasions, taking a VERY LARGE amount of pressure to release, meaning I tried very hard and couldn't get them to release in several tries, then pushed them extremely hard and got them to release. Not sure why, they seemed to work fine the next try. I've also just flat worn out several HKS loaders, the rims of the cartridges wore the points that hold the shells in, and locked up the loader (knob wouldnt turn, and couldnt release rounds) when I went to use it. It was back when I rode motorcycles a lot, (the old fashioned vibraty kind), and walked a LOT. The movement seems to have eventually worn through the points enough that they locked up. Turning the loader upside down allowed them to release. Best to look at them once in a while with that in mind, and toss any that start to get wear. They arent expensive, and one shouldnt be afraid to toss them if they dont work right or show wear. Had one or two HKS's come apart also. The spring loaded ball detent came out, so the center part wouldnt stay in any one position.
I've tended towards the Safarilands after using the HKS's for years. After using the Safarilands, which I like very much, and think they are defiantely faster than the HKS, I'm leaning abck to the HKS. They are easier to deal with if they dont work as expected. The Safarilands that seized up were Comp 1's I think, perhaps 2's tho. I really like the comp 3's, wish they made them for 44's. Not mentioned in the article, the comp 3's have a spring that slaps the rounds into the chambers when it releases.