A similar thing happened to me. I’m an adult rider who is very small and often put on ponies, and I’ve never liked peacock stirrups as a result, having ridden using them more than a few times. The rubber pops off, random things get caught on them, and the one time it would have been helpful, the rubber didn’t break. It was a weird sidewise fall from a spook, with my leg hanging in the stirrup, and my paddock boot halfway off. Fortunately, the pony didn’t move.
Before I knew this was a thing to do (flipping the stirrup leather off the wither when dismounting), I did rub a down jacket on one–I wasn’t hurt, but it did get a small rip. Obviously, not a life-or-death situation, but I’ve never had an instructor tell me this was a risk until a year or two ago.
I realize it’s not going to come to this, and the author of the article had an agenda, but IMHO it’s a question of “are more lives saved than injuries caused” by the design. I obviously don’t have data on this, as a rando Internet poster! But the argument that they are cheaper than better designs and therefore should be allowed isn’t all that persuasive to me–I know lots of lesson barns save on helmet “loner” costs, but it always makes me twitchy when I see a kid riding with an obviously expired helmet (a design from like, 15 years ago), or so ill-fitting there is no way to protect the kid.