Mayhap not, but asphyxia is def a case in which the death is significantly more painful then it looks. It can take up to 3 minutes to actualy lose conciousness. 3 minutes of your lungs feeling like they're on fire as an indeterminated number of blood vessels start to burst inside it. Drowning is a specially terrible.
But on death caused by animals, dogs/wolves and big cats are one thing, because these animals tend to be efficient killers and go for the neck and try to quickly kill their prey. Unlike those, a bear is an animal that doesn't care if you're dead by the time it starts to eat you. Bears are known to simply grab animals (and humans) and start eating them on the spot, regardless of what part they're actualy gnawing on.
In shorts, bears are jerks.
...actually, IIRC from forensics, it's speculated that most strangulation deaths involve either the victim falling unconscious, or their hearts stopping outright, due to heavy stimulation of the carotid sinus.
Thats the thing. It MAY take up to 3 minutes to actualy lose conciousness, it all depends on the set up and each person's individual characteristics.
Some victims, for example, die of cardiac arrest even before hypoxia sets in, for a variety of reasons, be it predisposition or how the strangulation takes place. In hangings, other factors may cause death before actual asphyxia, like the neck bearing and etc.
Keep in mind that strangulation and hanging are different things. In strangulation, the rope tightens around the neck on all sides, while in hanging, the pressure is mostly applied to the front and upper part of the neck, usualy, and the arteries may not be as affected.
There's also this one about drownings, this one phenomena that happens with some victims that, due to natural predisposition, experience a kind of "sudden death" upon diving into the cold water. These victims show none of the general signs of death by drowning or asphyxia (IE no ruptured blood vessels in the lungs, almost no liquid inside the respiratory system, no cyanosis, etc) since they die to a kind of neurogenic shock.