“Pub talk” is a thing, and “can’t discern from overengineered pub talk” makes sense.

“Can’t discern from overengineered public talk” is plausible, but it would be very unusual to phrase it that way.

It’s not really clear that he meant "public."

I meant a never ending stream of sophisticated ideas and precise data that leads nowhere. I used to watch every interview of the guy[1] and .. I always left the video empty minded.

[1] he seemed to have human values and of course knowledge about the topic

Ok, we're going down a rabbit hole here, but just to clarify, you meant "pub talk" as in the kind of conversation people have at a pub after a few beers? Or "public talk" as in a public speech, as nikofeyn suggested?

pub/bar sorry

No problem! You said exactly what you meant. And it got me interested so I'm watching the video for myself now.

i can see "overengineered pub talk" as a specific critique instead of them meaning public. i am probably wrong there. but the point still stands as it's rude and not important to make a mention of their english, especially when it seems what they meant is one of two things, both of which make sense.