If you design a Taser to be used at some distance, say 12 feet, with sufficient MV to penetrate clothing, it could cause pretty serious injury to someone if it hit bare skin. So, they don't. And the result is that the prongs may not penetrate clothing, especially in winter (which it isn't).
And if the suspect is high on uppers, it may not have much effect on him.
If indeed they hit this guy four times with a Taser, either he's very high on something or the Tasers somehow all failed.