The usual suspect for this is the lock cylinder switch in the driver's door (located inside the lock assembly). Many Nissans including the '15 Path have a function allowing the windows to be operated by turning the key cylinder to the lock position for two seconds (roll up) or the unlock position (roll down). When the switches go bad they often "false" a roll-down signal while the car is parked. The key fob can also be responsible, although that's generally user-error and not a malfunctioning fob. If the Unlock button on the fob is held for more than 3 seconds with the doors already unlocked, this will also roll the windows down. A fob in a crowded pants pocket with the button pressed inadvertently can cause it. However, if it has happened repeatedly, a "falsing" cylinder switch is the cause. Replace the driver's door lock assembly.
Have had this happen to me a number of times, presumably from my fob buttons getting pressed while in my pocket. One thing is for sure though - it invariably happens at night or right before a rain storm