I’ve been to a couple of parties where the birthday boy or girl won the final PTP prize. A normal reaction is to be happy for them, most children and definitely all the adults always are. Especially since everyone else tends to get something in a well planned version of the game too. I’m glad I don’t know anyone like you OP who would sulk over their child not winning the last “prize” 
It’s funny that the OP thinks anyone who disagrees with her would make their kids win. Er, no FastAway... we’re just not that precious about who wins! It’s a game FFS. FWIW we didn’t play it at my DS’s big party last year but I really did not think anything of the parents or entertainers who arranged for the birthday boy or girl to win at the other parties.
You sound bloody hard work OP. Please find a hobby.