I was not in the field but considering the mindset of our politicians/people I would say the vote rigging was done in the following methods:Army were deployed as consoling price for opposition their duty was to petrol the street not quelling the violence. if they had taken action against vote rigging happened before 30th dec. then we could see some differences but they were handicapped .
1) Vote boxes were stuffed with false ballot papers in the late night or early morning.
2) Many voters were obstructed or bullied on their way to voting centers. Their votes were already stuffed earlier.
3) Military and Police were just standby to watch over any extreme things happening and are recorded in video.
4) As far as I understand the mobile service was almost non-existent on the voting day. Newspapermen and others could not communicate or send pictures and data.
A fair election is not possible unless it is under a caretaker govt chaired by a former/sitting SC Judge.