Hal: No prob.
A tight leather corset? Okay, then without such implementation it would have only resulted in... ...what? What we all know and love? Then the corset would be a converging variable involved in the death, and likely necessary for its expedience. Any circumstances resulting in death without such asphyxia-inducing elements? For me, the important question is, can a healthy person, free of heart disease or related heart condition, free of asthma, free of epilepsy, etc. etc., and given all necessary conditions to continue life (adequate food, water, medical care), could they die? The likely problem will be, that once all those are met, there is one condition that, by virtue of tickle-torture, cannot -- adequate rest. It is, as I understand it, possible to die of sleep deprivation. Tickle torture and sleep being mutually exclusive... well, that pretty much nails it.
I understand your premise of "if shot, death by lead poisoning" in my analogy, but think it's overreaching. Some Native Americans had developed a practice of dealing with a captive enemy by sewing him into an animal hide, dipping it in water, and letting it dry in the desert heat. The heat would cause it to shrink, and result in a crushing asphyxia. Remove the animal skin, and you've just got a guy in the desert -- and not one dying of asphyxia. In your example, remove the corset, and you've just got someone being tickled, or vice-versa... Neither seems to immediately reach the requirements for death in and of itself, and I think that's what we're looking for... To avoid sleep deprivation and related effects as a converging variable, let's limit the torture length to, say 24-48 hours... Is it possible to kill someone healthy with tickling alone, making sure all needs are met, save rest, and with no other bells and whistles (or corsets) attached?
Madman