So maybe frankness wasn't the cause. It's even possible they were interested in his perspective and wanted to get his honest opinion before they lost the opportunity. Or maybe they had nearly made a final decision but not quite and wanted this conversation to see if what they learned made a difference either way.
On a separate(?) topic, a lot of tech organizations seem to be fond of saying they want to hear all ideas and judge the ideas on their merits, but when you actually say something that goes against popular opinion or conventional thinking within the organization, people aren't open to it or are even hostile or dismissive. In my opinion, it's not as easy for humans to be objective and open-minded as we think.