Two problems: IIED is a civil tort, not a crime, misdemeanor or otherwise. Second, the rule you state usually doesn't exist; many states have abolished the misdemeanor manslaughter rule or limited iy to a narrow class of misdemeanors, so that death in the course of a misdemeanor isn’t automatically manslaughter, and in states that retain it the class of manslaughter it becomes is a often a wobbler (can itself be a misdemeanor, or a felony, not always a felony.)