That's a good point. It's better to be safe than sorry in a survival situation. However any true bushcraft expert would likely question how you're using the knife and insist that if used properly, the knife is perfectly safe without a guard. Mora knives come with or without guards and it's generally accepted that the guard just gets in the way when it comes to doing bushcraft stuff.

My perfect field knife is the one I have that day...because the ones I leave at home can't help me. FWIW, this is the knife I most often take to the 'field':
http://images.cabelas.com/is/image/cabelas/s7_516498_imageset_02?