Wow... that's quite an amount. So human milk doesn't "expire"? Why does cow milk expire then, and what exactly is expiry in the context of milk?
It's not commonly done for cow's milk because (1) fresh milk is usually readily available and (2) adults will complain about the taste.
With breast milk, the supply is more limited and an infant won't tell you the taste is off (but they might refuse to drink it!).
But yeah, in the end when that's all that's on the menu... hunger takes over :-)
I imagine pumping without consideration for that causes over-production (and the desire to pump more to relieve the 'pressure').
I'd say they froze the milk in question though, just thought I'd mention it.
I'm not saying you're wrong, but my wife and I get our milk from a single cow. It's tested for harmful bacteria bi-monthly and we wash our own containers beforehand. Do we run a greater risk than purchasing pasteurized milk from the supermarket? Probably, but the flavor and nutrition make it worth it for us.
Additionally, the raw yogurt eventually does turn to curd if put in an environment > ~50 degrees F. If you strain it through a cheesecloth, you have a very soft cream cheese. We don't make a habit out of doing that though -- leaving milk out overnight seems like a bad idea regardless of the source.
Raw milk isn't actually banned in most of the developed world. The EU, for example, has non-binding rules that allow vendors to sell raw milk as long as it is done at a small scale, like your case, where the animals are tested often and the scale of the operation doesn't endanger the health of the average consumer. In most EU countries you can "time share" or own a cow that provides raw milk for your household but you can't openly sell it at a supermarket. Countries like France, where raw milk is culturally preferred (something like 20% of cheeses in France are made from raw milk), have a much much higher incidence of food poisoning from dairy than any of the countries where milk is always pasteurized.
I love raw milk and miss it dearly since I moved to the United States but there is nearly a century of evidence that raw milk at commercial scale is an unacceptable risk to public health. So much so that there isn't a single country in the developed world that doesn't strictly regulate raw milk products and all of them do so for public safety reasons.
In the past I have done the family milk cow/goat thing, as well as canning, natural fermentation, and cheese-making. So I've done some reading on the topics. I sorely miss raw jersey milk on a daily basis. That stuff is wonderful.
There are spores of c. botulinum everywhere, but they don't normally cause a problem unless there's a deoxygenated environment (e.g. in the core of a sausage — Latin botulus, hence the name).
The trouble with poorly-canned goods is that they are not exposed to oxygen, other micro-organisms have been killed off, but c. botulinum has survived: that's a perfect breeding ground for the stuff.