I did not see the initial sting. These photos were taken of the spider after it had been paralyzed by the wasp. The wasp was in the process of excavating a burrow into which it would eventually drag the spider. Periodically the wasp would break from digging to check on its prey (I came upon the pair during one of these check-ins). I temporarily righted the spider for a dorsal shot. The spider was still alive and trembled slightly when I disturbed it. Unfortunately, I wasn't able to stay and observe the whole process.

I assume the wasp had already dragged the spider some distance since these spiders aren't normally found out in the open and staged it for easy access once its burrow was completed.

I think whether the wasp mauls/removes legs from the spider varies by wasp species.

I've seen them remove legs, and, seem to maybe disable the spinnerets, by chewing them up as well.

I've also seen them just sting grab and fly, but they usually don't get far, and it makes me wonder if they are flying away from a clumsy observer!