Of the many times I've walked down there, the most worrying was in the company of one Mark Twight. I was guiding a disabled lad and there was a film crew on hand - to record our ascent of the Aiguille du Tour - and sundry helpers, of which Mark was one. He was carrying an enormous and heavy TV camera. He refused to be roped up as he said it was totally unnecessary due to the lack of crevasses...

Hi Jon - I tend to agree with Mark Twight, in spite of the obvious contradiction of this picture!
There are a lot of places that were "crevasse free" that have some huge holes. The descent of the Midi arete and around the base of the midi S face come to mind... and that was 10 years ago...
My view always tended to be unless you were up to your waist it was a crack, not a crevasse. Best not to look too closely at those "punch throughs" was one lesson I quickly learnt.

No, it's more complicated - and interestng - than that. I'll email you.