USB Power Surge/Device shocked me on touch

Isnt my computer case itself (NZXT H440) grounded? Because the case touches the psu and the psu has a 3 pin prong?

I was kind of hoping that you would not ask that

If you can find an unpainted surface to touch, then yes, that will discharge the static in your body. You can discharge thru the paint, but not as well as touching bare metal.

There is a slight risk to the components inside of the case during that discharge - so it is not as ideal as touching something that was meant to carry 20kv to 30kv to ground.

Tell you what. I will just plug in that spare PSU and keep it in the corner of my desk.

That should keep your replacement controller happy