No. Had Sinsull fallen into a fissure that would not be an urban legend. However, it would have been a a truly strange thing to do. I too have been on a glacier- not only do they issue the same kind of non-slip 'bunny boot' to every person but the crew is even overly vigilant in watching everyone.

So, Mary, had you slipped into a fissure you should have been sued. Sorry.