It's not at all clear to me that this is the case. I mean, sure, there are obviously big problems with the app's design and implementation. But there are ample signs of deeper problems with the customer (and indeed, TFA alludes to some of it).

The fact that the Party insisted on keeping specifics about the app secret until the last minute was the first big red flag to me. With the customer making such a demand about a product that's intended to be widely distributed with zero ramp-up time, they had at least two strikes against them from the start.

Further mess-ups outside the app development, like using the same phone lines for support and for reporting, are mistakes that don't obviously fall on the shoulders of the developer.

The customer - the Iowa Democratic Party - probably needs to bear at least part of the blame for this. It's true that an experienced developer might have given their customer better guidance, but that doesn't absolve the Party from these mistakes.