Basice maintenance of a firearm is the owners responsibility and if the owner is not smart enough to handle this task....then tough *.
Basic maitenance is indeed the responsiblity of the owner. If the firing pin drops on a chambered round when disengaging the saftey (and it had to be to cycle the round out of the chamber) of the rifle, then it is doing something it wasn't designed to do and I don't think it is the person who buys it place to go tinkering with it, especially if they have no idea what they are doing. Sure cleaning and maintenance. Filing and altering the weapon yourself is asking for trouble unless you are trained and know what you are doing. If my rifle did something like this I would take it to a smith and have it fixed asap. There is no excuse for having the gun pointed in the direction of anything valuable. A gun that fires when disengaging the safety, though, is broken and Remington is offering to fix it.