Would you pull out a ram stick or graphics card while you're computer was still on?
Yes. Even a CPU.
In a hotswap capable high availability serverI think he was more asking is the PSU ok. The fact that someone wanted to energize a power supply and THEN connect wires well I mean that is just asinine. Some people should just buy Apple products and treat them like magical toasters. Plug it in, use it, throw it away.