I'm going to make a big assumption here. The A320 got airborne. Both cockpit members probably soiled their underwear shortly before, during and after the event. There would have been an exchange of radio calls and certainly a discussion between them. All the time the CVR would have been running. I'll bet they landed at wherever and the thought of popping the C/B for the CVR never went through their minds. After 30 minutes or two hours (the most likely CVR durations) the most pertinent data would have been over-written.