The thing about handling hots is that you're not guaranteed to be bitten or even struck at. Especially with the copperhead/cottonmouth genus. They're pretty docile (despite popular belief due to media and fear). But it's one of those things where it WILL happen at some point if you free-hand them. It's inevitable that you'll pick up a grouchy one and be complacent at some point.
That happens with non-venomous snakes too. Kingsnakes are legendarily chill. But for every 10 I find there's 1 that isn't happy or 1 that goes 0-100 for no particular reason while holding it. That's not a big deal with a king, the punishment is more severe with a spicy snake.