There are plenty of company rules and government regulations regarding the storage and handling of these materials. There is more material like this on the highways than most people know about, and around their homes, if they, like me, live in oilfield country. The problem right now, the way I'd guess is that because the industry is picking up, they are hiring less experienced hands, and perhaps they aren't taking this seriously enough. Those radioactive materials are specially containerized, and a strict CoC is supposed to be maintained at all times. Somewhere, someone is sweating on this one because when they find the paperwork, the last guy to sign for it will probably lose his job, and not be able to work in the field again. It's viewed pretty seriously, as it should be. That container, although not very large, or really all that potent as these things go, could easily poison a body of water that a municipality sources water from, or as mentioned earlier, spread atmospherically with not much technical knowledge or skill, or effort.
In other industries who also have to deal with this and similar issues, we probably just don't hear about mishaps. I have read about this issue on an international scale and one that bothers me perhaps most is all the nuclear generators that were basically abandoned by the USSR. They issued small scale (two man carry sized) generators for their far north observation stations that were no longer needed after the breakup. Now, the material gives off a nice warmth, and farmers are using them for space heaters! But many (dozens? hundreds?) are completely unaccounted for. And they are much larger and more potent than this little package Halliburton lost.