The following ITV documentary at approx 6.20 mins in shows David Boutflour as stating that Sheila's nails were still perfect:
http://www.youtube.com/watch?v=_i2CjYDJGToIs this surprising? My nails are approx 4mm above my fingertip and have in the past been longer. However, short or long they rarely break despite engaging in a wide variety of activities

. Admittedly I have never pulled a trigger on the type of rifle used, but would this be any more hazaradous to a set of fingernails than other activities? Occasionally one of my nails breaks, chips or splits but this seems unrelated to any activity.
Pre political correctness I believe males would often say to females "Be careful you don't break your nails". But nails are made of keratin, a tough biological matter:
http://en.wikipedia.org/wiki/Keratin