What I did see was there was big turnout, a lot more people turned up then usual. Is this true?
While I was home with a sick kid, I did see a lot of people heading in.
The way the carcasses are done are very opaque by design. You vote in a small group, and send someone to report the votes to the next larger group, and so on to the country party chair.
At any step in the chain the votes can (and have) been changed. Romney DID NOT win Iowa, but the GOP decided to do it The Paulites called him out but it was too late.
The app was supposed to stop all the back room deals. Idea was it to be tabulated in real time. Considering the amount of money the big tech firms have dumped into the Dem coffers, this is simple task.
My guess is the county and state chairs started seeing results they did not want pretty early on. Remember, real time updates. In the past, you just ignored the votes (hand written most often on scraps of paper) and told the reporter to “Be accurate”. However they had all these electronic votes that were pouring in for the wrong candidate.
What to do? Crash the server. Next, blame Russia.
I expect by the end of the day there will be calls that Russia meddled in the Iowa Carcasses because Trump promised them Alaska. No sarcasm.