Apparently there has been a problem with the trigger mechanism for a long time and the rifle can go off by simply turning the safety off. It seems to happen more often in cold weather. It's been an issue for a while but coming more to light with all the class action lawsuits.
http://www.cbsnews.com/news/popular-remington-700-rifle-linked-to-potentially-deadly-defects/
http://www.cbsnews.com/news/popular-remington-700-rifle-linked-to-potentially-deadly-defects/