When I worked at a clinic we often recommended that people not use pigs ears or rawhide, mostly because a lot of people do not supervise their dogs with toys. Sadly, most people think--and understandably so--that something sold specifically for a certain kind of animal has to be safe. But time and again I've seen that's not true. I saw a puppy who was given the wrong size of Kong and almost died because he inhaled the whole thing. We had to scope it out of him. Rawhides can be dangerous--as people have said--if dogs eat them quickly without breaking them down enough. Labs seem especially prone to that kind of behavior, and I've seen dogs very sick because they got blockages due to ingesting large pieces of rawhide or nearly whole pigs ears.
Ultimately, though, I think it's about a larger lesson every pet owner needs to learn. Don't trust packaging. Do your own research. Make sure all toys and things you feed to your animal are safe for YOUR particular animal. And always, always supervise your pet when they get a new toy until you're as sure as you can ever be that the toy is not a potential hazard. I wouldn't say NOT to give pigs ears or rawhide, but I would say that if your dog has one of these items, be in the same room while they play with it to make sure they're not just wolfing it down.
As for bones, I read from a source I believe to be credible that one of the reasons perforation is LESS of a problem in wild canines is that they ingest a lot of their preys' fur as well, which is thought to help cushion bone fragments in the intestines. I found it interesting, so I'm including it more as a point of interest than anything else. If anyone has any further information on the hypothesis--proving or disproving--please speak up, I always like to learn. In any case, there are still definitely wild canines that die from perforation. Again, I think it's just a matter of educating yourself a much as you can, and then using that knowledge to make decisions that are best for you and your pet. Those decisions won't always be the same for every animal. Calculated risks minimized as much as possible is--in my opinion--the name of the game.