The only time you might want to listen to a security engineer is when they percieve a problem that the builder doesnt and even then my professional experience with security engineers is way too many are boys who cry wolf and parrot whatever the sweeping tools say.
Phrased another way i would trust an engineer who put up a bridge if they said the bridge had issues over an inspector whose paycheck is very much dependent on not finding issues.
That depends quite a bit on what was being discussed. If it's the engineer's work specifically, and what they did and why, that's one thing. If it's an engineer making claims about specific encryption algorithms that they chose to use or not use in the software they wrote which is contradicted by a security professional, you should probably trust he security professional.
This seems to me a case of the latter. A software engineer making claims about things that are not their subject of authority, or at least not what they were hired for, and thus have less reason to be listened to about by their employer.
Google AI Ethicist "inspection" though....
I am not convinced this is true AI. But if and when true AI happens, and a lot of engineers claim that the machines are suffering horribly, we should take that seriously, regardless of whether the engineers have been accredited to recognize suffering in others.
I am a programmer. I am not a security expert. I can have opinions on security concerns, but they carry less weight both within and outside my company because I am not a professional security engineer. I can still recognize obvious problems, but I would correctly not be trusted to roll my own encryption.