First, I don’t think this was instantaneous. Depends on how high the voltage was.

Regardless of that, I wanted to point out that I once had a third-degree burn next to my ankle made by the escape pipe from a motorbike. It barely hurt at all, and it smelled like steaks. Thing is, the nerve terminals burn, and so you don’t feel any pain. But it was ugly, following days I had to keep it clean… And the mark lasted a few years.