I have a suspicion that my torts professor is going to throw a conversion hypo related to the loss of a body part on the examination.
What is the case law on this? Off the bat, I assume that you would not have an actionable claim if you voluntarily surrendered a body part. But what if someone cuts your hair off while sleeping–conversion? (battery, obviously)
Law school exams require analysis. Just because a case decided something a certain way does not mean every court will find it that way. Not to mention, courts often change the law based on changes in time or because of a persuasive argument (granted they can only change the law if not bound by precedent from a higher court).
In your hypo, argue both conversion and battery. Also discuss trespass to chattels as an alternate possibility. Cite the case you listed and perhaps use it to support a conclusion that a conversion charge is unlikely to succeed, while a battery charge will probably succeed. Do not, however, completely skip conversion. You are being graded on your issue spotting AND analytical skills. Failure to spot a potential issue and analyze it will cost you points.