A question regarding Sean Carroll’s example of entanglement

I was watching a lecture by him, and he used an example of radioactive decay producing two electrons flying in opposite directions with both having either spin up or spin down (relative to any axis of measurement).

My question is what is the motivation for him to use this example for entanglement rather than the EPR example of opposite spin entangled electrons that the layperson is familiar with? I was really confused at first until I learned that such a decay actually exists.

Also, what is the actual type of decay that Sean Carroll cites?