There is a chance, that all is by incapability or random. But I don't believe this. All people involved have strong motives.
And:
Why was Sanders leading by far before the election and Buttie made it in the end?
Why Buttie knew the "results"? Look carefully the results published by the Sanders campaign differ remarkable. Nobody had close results like Buttie.
My theory is that Buttie and the 2016 Clinton Campaign have stolen the election from Sanders and then caused chaos by sabotage in order to hide it. Even the backup phone system was not working at the evening of the election - not only the app.