Final answer:
Joan could not be retried after her death due to the principle of double jeopardy, which prevents individuals from being tried again for the same crime after being acquitted. However, this principle does not apply to civil cases.
Step-by-step explanation:
Joan could not be immediately retried after her death because individuals cannot be subject to double jeopardy, which means they cannot be tried again for a crime after being acquitted of it in an earlier trial. This legal principle prevents the government from repeatedly prosecuting someone for the same offense. However, this restriction does not apply to civil cases, where individuals can still be sued after being acquitted in a criminal case.