It may be one of the reason's for when you see stories about a death and an almost immediate cremation.
If the insurance company is going to pay out 250k,500k or more, a fast 5 sec blood, tissue or hair sample for $50 is well worth the investment to them. Myself I wouldn't take the chance of having the insurance company screwing my family over. If people don't want to pay the premium then don't use nicotine at all or take your chances.