What you're seeing is what's called the "activity stream" below each suggestion. In some cases when you see people vote multiple times they're simply switching their ranking. That's normal.
If you see someone applying the same ranking twice in a row they may simply be trying to confirm their ranking.
In any case, in contrast to the earlier sabotaged voting process, we're talking about a small pool of approved voters here. Duplicate rankings will not slip past us, and I'll use the most recent ranking provided by each person when tallying the scores.