If I understand the IDP press release, the non-tech part was really just going back to the paper records as part of verifying the nature of the tech problem, which was that the app was gathering data correctly but not including all the data in its reporting function.
There are three sets of results data reported through the app (first alignment, second alignment, state delegate equivalents).
https://www.nytimes.com/2020/02/06/upshot/iowa-caucuses-erro...
There's also some dispute about whether satellite caucus rules are being interpreted correctly. (Currently, it's being interpreted in a way that's friendly to Sanders.)
What a complete mess.
https://twitter.com/AdrienneRoyer/status/1224796527392108545
I have bigger issues with caucuses in general and in Iowa specifically disenfranchising people from being able to vote at all, but that doesn't excuse that this was also terribly implemented.
It's not clear he'll win, I'd maybe even bet on a narrow-loss though we'll know for sure in 2 hours, but all campaigns agree was a strong showing. If not first place, likely second. His polling had him doing worse, so delays in him celebrating beating expectations are bad. And it's undisputed that this bug happened early in the process, so at a time when nobody had any idea who this would hurt/help.
(Also, the issues weren't all app-related. My understanding is that the non-tech issues related to counts took much longer to figure out.)