As long as the vote is counted in secrecy and not verified, term limits are irrelevant.
Assuming the vote that gets a candidate into office is the real vote, I don't see why that person can't stay in as long as he or she can continue to be elected. The longer you're in, the better you should be able to understand how to serve more effectively. If you're in it just for the power trip, of course, you will also know better how to remain in power even if you're not doing a very good job. But I think the balance tips toward not having term limits.