In reply to JimR:
Snagging a foot (or, worse, a crampon) in the heel loop on a pair of Ronhills seems to be quite a common problem - it's also a summer issue if you wear studded things such as Mudclaws. I too cut off the loops (wear one pair in summer, two in winter) and I know of other people who do the same.
Potentially the worst crampon-snagging moment I've had came years ago on thankfully quite a flat bit of Stob Binnein. Managed to impale the rubberised shaft grip of a walking axe with a front point in a way that I don't think I could easily do again if I tried. Did this mid-stride and suddenly found myself hopping around on the other leg for a few seconds wondering what on earth had happened. The axe is still in use and has had duct tape covering the flappy bit of rubber from that day to this.
More seriously, I've seen someone catch a crampon on a stock fence while semi-vaulting it in a jaunty fashion. That resulted in red snow.