Remember when you had five SP to assign, but if you clicked the button really fast you could assign a lot more than 5 SP? I think there was also something about leaving the page and coming back allowing you to reassign the SP even though it seems to have already been assigned.
All I know is, at some point Bort actually ran a check when you click submit and if the numbers didn't agree with how many SP you had, the submission failed and it wouldn't assign the SP.
I think the principle is the same with voting. If you click on "vote" on a replay it locks, but if you click it ten times before it locks it shows up as having 10 votes.