Ok wait the numbers seem completely f**ked.
https://twitter.com/aaronfoldenauer/status/1409976473977557003?s=20
Someone noted above that the minor candidates were having extremely high exhaust rates. If that’s caused by these phantom votes than they may actually not be factoring into the final round count, meaning the current final round is accurate. If not...oh boy.
So while the inclusion of a bunch of dummy voters is indeed a massive screw up, I believe the elimination of 3 candidates in round 8 is correct.
There are situations in RCV tabulation where it is possible to eliminate multiple candidates simultanously. In this situation, the combined votes of the 5th, 6th, and 7th place candidates were neither enough to give any candidate a majority, nor were they enough to allow any lower candidate to leapfrog the 4th place candidate. Therefore, regardless of how the 7th-5th place votes were distributed, the top 4 candidates were going to remain the same, so there is no reason not to eliminate the bottom 3 at the same time.