I have had this type of thing happen to me before, but not with a Remington 700...
My father owns an old Winchester Model 70 bolt action in .243 Win. It is old and ugly but dead nuts accurate and capable of MOA accuracy. I used that rifle to take my first several deer and one turkey (@ around 170 yards).
One thing I do not like about that rifle is that the bolt cannot be opened with the safey on. Not typically an issue, but this particular rifle developed a problem... On my last deer hunt with that rifle, I forgot to take it off safety first, and attempted to open the bolt on safe. Discovering the bolt would not open, I pushed the safety off with my thumb, when the rifle suddenly discharged (shooting a hole in the roof of my uncle's chevy suburban).
A year later, my brother replicated the problem after a deer hunt, discharging a round into the air. Seemingly the cause was the same - attempting to open the bolt on safe, then pushing the safety forward, causing the rifle to discharge.
No fault of the design, IMO, just an old rifle that developed a mechanical failure.
Valuable lessons confirmed... ALWAYS have your firearm pointed in a safe direction. I also learned that I prefer bolt guns that can be opened with the safety on ; )