Reading some more, it does look like Zillow was in fact leveraging humans in the loop https://venturebeat.com/2019/12/11/why-explainable-ai-is-ind.... What seems like a likely explanation is that the proper balance between machine and human judgement was not calibrated to this current market.
"Part of the challenge of Zillow Offers’ human-in-the-loop system — any such system, really — is finding the balance between humans and machines. “In order to optimize this human-in-the-loop system, we’d like to figure out when the human is best, when an assistive situation is best, and […] when a machine is best,” said Fagnan."
"Part of the challenge of Zillow Offers’ human-in-the-loop system — any such system, really — is finding the balance between humans and machines. “In order to optimize this human-in-the-loop system, we’d like to figure out when the human is best, when an assistive situation is best, and […] when a machine is best,” said Fagnan."