My approach would have been to go with the new idea and see what discussion can come out of it. If they don't have time to get into it, that's one thing but if they are simply not open-minded to new ideas, I don't want to work there.
In another profession like say a specialized electrical engineer, there may be only a few positions posted a month and a handful of qualified people so both the engineer and the company would be desperate that they could together be a fit.
This story was about an anecdotal experience where the power dynamic was fairly equal
Certainly when I got my first job I felt like I was there to take a job, not seeing if the company was a good fit.
But as someone with experience, looking for higher-level positions, ideally with some time on your hands / savings in the bank to take your time interviewing around? Yeah, it should totally be a two-way street.
"Experienced software developer" is a comically in-demand job title. It's good to know that fact, and to be proportionately selective.
In that case bad luck but if they send a dick to interview you it is more likely that the rest of them are also gonna be dicks. I like companies where you actually interview with some of the people you will be working with at least as the last interview round.
In terms of your idea that a single interviewer should turn you off from working for a company, possibly. Companies can be pretty big. I am skeptical that there are many medium or large companies that can prevent all negative interviewing experiences. Especially if the negative experience is, "I saw my interviewer make a facial expression that I over-analyzed and made a huge narrative about."
That said, if you want to use that as a signal that's your prerogative. My guess is that you'd mostly get false negatives from this signal but if you have many options for employment that's hardly a major problem.
Companies can be large and in that case it's likely you will be encountering a fair number of people you won't like while there anyway. The question is whether you interview with "random interviewer of the day" (still bad if that's a bad apple but if the company is large you might take your chances while if the company is small, it's likely this is 'their best' or you will work closely with this person) or if you're actually interviewing with the team members you'll work with. If the company is large but you know you are interviewing with the team members you'll be working with and the feeling just isn't there or worse, then I think I'd take the possible false positive if I wasn't in a bind for a job.
At my current place for example I interviewed with a bunch of people in various rounds, from the typical HR stuff at the front, through various layers from CTO, my boss, our architect and then a sample of people from my immediate team. All of them very pleasant, had the best interview experience ever with the architect. We had a great discussion of pros and cons of various choices I made for the code I had to write, alternative approaches etc. Really awesome. Felt basically like a regular working session, no leetcode quizzing BS.
Previously I have interviewed with other companies where it just became clear after some time that the company and I were on very different terms with regards to how we think software development should work. A different interviewer might have been able to 'hide' some of it and I might have joined that company and been miserable.
I would have no problem saying "many people use MVC to mean 3 tier and other people use it to mean XYZ".
It is very difficult to be completely technically correct. It is also rare that one needs to be completely technically correct in conversation.
However, doing that in front of the tech-lead his boss is likely to be different from a fair discussion. Disagreement about technical architecture is fine. Doing so in front of higher management is likely a different ball game.
Getting into a lively technical discussion when you can see how well people can control their egos to find out the best course of action is very valuable. If I had a chance during an interview to find out how people behave in those circumstances I would definitely go for it. Who knows maybe the "boss" would be present in future technical discussions as well, I wouldn't want his presenc to change the discourse negatively.
And as I've personally been in positions like that (being the tech lead with the boss on the call), I'm usually thrilled to learn new information and discuss technical things, raising my opinion of the interviewee greatly.
Maybe that's because I come from a very straight forward culture where political subterfuge is frowned upon, but it wouldn't actually look very good to me if a member of my team would subtly alter a technical matter for the worse because of political pressure. Would I be able to trust that person? I would always have this doubt that they are "playing a deeper game", regardless if it was for my benefit or not.
And if the tech lead can't admit in front of their manager to not knowing everything? That's a sign of a toxic workplace.
I'm not ashamed to admit that I have previously found myself in a situation similar to the tech lead: the interviewee gave a solution that I didn't know about - one that could be considered better - and my manager was in the room interviewing with me. I told the interviewee that this is a new direction I haven't thought about until now. It's important, otherwise we can't continue an honest discussion about the solution.
You cover both bases, give the blogspam answer that most view is the "right" one, but also show that you have a much deeper understanding.
My favorite question when interviewing node.js candidates was around this type of ambiguity- "Is node.js single threaded or multithreaded?" and most would immediately shout back "single threaded!" but the reality is that its a bit more complicated than that, its a single threaded event loop backed by a thread pool, and I wouldn't ever hold a "single threaded!" answer against them, but start to ask leading questions as to what happens when we have say 5 requests all come in more or less at the same time to see if they really understood how things work. And the point is not to gotcha! them, its just to start a discussion- though if they reply back "well its complicated..." then I know they probably are already there.
In the context of MVC though, I feel this is really overly pedantic. MVC is an idea that is never actually implemented in purity, and understanding the basic idea is all that is really needed, outside of maybe very specific roles implementing web frameworks.
And there are essentially always nuances. So that's not really a controversial statement. At which point, the tech lead can accept the answer as pretty much what they were looking for or can probe further if it's actually the nuances they're interested in.
Why not say "there are many similarities and some differences, they're similar in these ways..."
I would probably try to give a full answer, such as "there's a widely-held concept X, but my understanding is that this is not completely correct, and in fact a better model is Y." A technical lead that can't work with an answer like that is one I probably don't want to work with.