In reply to Jon Read:
That crossed my mind for what you might have been thinking, but to be honest I don't see why anyone would buy a 600 quid top of the range shell jacket to wear while belaying at Curbar or Ramshaw. And I have a sneaky, probably class-based chip-on-the-shoulder, sort of idea that people who spend 500-600 quid on a shell for winter climbing and skiing would have other coats to take along to the crag with them that might be better suited for a winter day on the grit.
FWIW, the Odin is relatively long, but when I'm wearing it under my harness winter climbing it does not get in the way at all if I need to pee. Actually, to my mind a far more annoying oversight (? or possibly bad design choice) is the matching Vanir LT trousers do no have a double fly zip. This leads to some slightly obscene looking fumbling in the crotch area when trying to unzip them to have a pee!