Does divorce occur if a husband stipulates that his wife not spend the night outside the marital home after 12:0 AM, except in two cases (his death or an oath of divorce), and then the wife stays at her family's home after 12:0 AM due to an emergency, not knowing that what the husband meant by "spending the night" was staying after that time?

A man's statement to his wife, "And the second, you know it," is neither an explicit divorce pronouncement (sarih) nor an implicit one (kinayah). No ruling of a divorce oath (yamin (definition) al-talaq (definition)) is incurred by his mere intention without uttering the words. Therefore, no divorce occurred when the wife stayed at her family's home.