[Yo-Yo]

Because the officer tried to stop him so he could arrest him (see the article) instead the man ran and was tasered. Obviously man couldn’t run very fast with all those rain drops impeding his progress

Clearly a naked 63 year old man shouldn't be able to outrun a physically fit police officer. Not for very long, anyway.

Tasers are not a "because I said so" magic wand to be used because you don't want to tire yourself out chasing someone. Their use is governed by the same rules of deadly force as firearms.

Suspect making you run? Too bad. That does not authorize the use of a Taser. Suspect holding a knife or large stick, and approaching the suspect is unduly dangerous? Now you can taze the bro.

[Nifster]

Tasers are used to force compliance. They even get used when suspect is on the ground