Byron, a law student, needed a pen to write an exam.
Sarah, another law student, sold him spare pen for $1.29.
During the exam, the pen stopped working. Frustrated, Byron stopped taking the exam and failed the course. His grade point average slipped below the required standard, and he flunked out of law school. Thinking that he learned something useful in law school, he sued Sarah for the $2 million difference between what he would have earned as a lawyer and what he was likely to earn without a law degree.
What body of law applies to this transaction?