Consensual activity, let people assume their own risks. For instance asphyxia at the point of orgasm is often practiced, along with other activities, there is not intent to harm. If some dumbass chokes on his gag while handcuffed it is largely his own fault, he chose to be bound and gagged.
Let nature thin the herd, it is a good very natural process. Prove intent to harm and then by all means prosecute, otherwise let the genepool self chlorinate.