We now know from the spoilers that the overseas votes played a major role in the final results. A large chunk of those should have come through online voting.
A cursory look at the site will tell you that it has a big hole. 4 lines of code and you can send votes non-stop - day and night. Even the restriction of 1 vote per id wouldn't stop this unless they verify the validity of email ids. They don't validate the ids, otherwise we would have been getting confirmation mails.
I think they should either put in place a better system with IP validations and all or they should totally scrap the online voting.