I believe that most of the raw paleos on this site are from 1st world countries, so their meat will have been carefully inspected, there are a lot of laws on hygiene etc.
Plenty of laws, not enough officials to control everything. We have a consumer program here on tele that targerts people who swindle others or make noise whenever the draconian EU wants to overwrite our local laws on additives (we dont like them, they do like them). They have targeted so many super marked butchers and found stuff that turns stomaches. Brand, high deli price supermarkeds even.
When I have been traveling to poor nations, I have never gotten sick from eating meat. Most of the meat I eat is slaughtered on the spot. It is not like in our 1st world country laying for days in a fridge only to be repacked, and repacked to extend the last date for sales. Here is how a piece of meat goes through the store: It starts out as large cuts. Roasts eg. Then when the roast is past last legla day for sale. it is turned into steaks which when they are done are turned into meat pieces and spices steaks, which....ground beef etc.. its nasty. So just because we live in a place with money does not mean we get the good stuff. In fact, I find often that it is opposite. We eat old milking cows, unripened fruit and veggies with no nutrutional value. Hoooray for all my money. What I am getting at is that I would not use the fact that we live where we live as a carte blanche of trust in the supermarked butchers.
They do it because they get away with it. 95% of the time. So it pays to speculate in it. You are cought every so often which cost you so much, but you make more by cheating and paying the fine.
Never gotten infected though. But just yesterday I read how some poor bloke found a large infected boil in his ham roast. So much for checking.