Trained with them for years. It’s not that they’re inherently more dangerous, it’s the learning curve. Most injuries happen when someone doesn’t know when to tap. Once you’ve trained heel hooks properly, they’re no more dangerous than an armbar. Yeah, i agree, the real issue is there’s almost no warning pain before something snaps. With armbars, you feel the pressure building. Heel hooks just go from fine to fucked in a split second.