In the following sentence are may and might interchangeable? There is no question of permission here, only possibility. The modal leads into a present perfect construction, which means the action begins in the past. It's been noted in other discussions that might is the past tense of may, but that is usually met by the denial that modals have a past tense. Are both may and might indisputably grammatically correct in the sentence?
The police then grill Philip about his involvement with the young woman and imply that the fight may (might) have been a setup.