“The only endemic snake in the US that will kill an adult is a coral snake.”
The victim in this story notwithstanding.
I’m assuming from your screen name that your are an MD. If an MD is present or even an EMS responder I would probably defer to their better judgment in that particular case. But if I or a family member is bit by a venomous snake somewhere many miles from help, I intend to use a stun gun in the same way others have and asserted it saved their lives. Of course I would not substitute this for getting the first available professional medical attention.
When I was a kid, we carried a snake bite kit with our camping gear. This apparently included something to cut the bitten area open more to help increase blood flow and get rid of the poison. Of course, it is now considered useless and even counterproductive. The shock treatment might be the same or it might only work for some very select cases based on the many experiences. And maybe medical science will further test these to determine when they might be helpful. But until there is more evidence otherwise, I consider this to be a reasonable response in rare cases in which immediate medical attention is unavailable.
I have treated many snake bites. The gentleman in question died due to an underlying heart condition. The fact is only about 1/3 of rattlesnake bites are envenomnated and far more harm is done to snake bite victims by well meaning people trying to help than by the snake. If you choose to use an ineffective and likely harmful procedure that is up to you but time would be better spent seeking medical care.
Even if the bite is envenomnated you have hours not minutes to seek help and there are satellite devices that are inexpensive and can summon help even in the most remote areas. I would invest in one of those rather than a taser. And in the wilderness I carry a real gun that can help with 2 and 4 legged predators not a taser....