I don't know.. but I like the generation of randomness if there is no real meaningful way to sort out the voting collusion problem.
Only if randomness can be proven, and I think we already have a nice tool for that made by member Bitmover:https://bitcoindata.science/giveaway-manager/
I am not surprised to see cheating in this competition, and I remember something similar happened with voting in discord.
Ah yes, the good old discord bitcointalk pizza day voting where some guy brought bunch of brand new Discord accounts to bitcointalk server (that have nothing to do with bitcointalk) just to vote for him, those votes were accepted and he shared the 1st prize. 
Current voting system is better but we can see similar behavior when money is involved.