Tom was listening mostly as Charlie, the practioner, engaged with Jim, the outside objective observor, discussed the issues associated with trying to change the internals of pushup greens. Amateur greenkeepers think it is all so simple to just change a slope here or there.
Since the classic guys like Flynn were mostly designing greens for surface drainage changing the slopes without dealing with the drainage is a silly endeavor.
Jim simply said "lower the green speeds". This idea of course is too simple and rational to be adopted by a bunch of crazed golfers at a golf club!
I recall our conversation at our #13 green where Jim pointed out how you need to start from the back of the green if you want to think about the front ( this is when I started to feel good about my day job!). They also discussed the impact of topdressing over decades and the difference between different grasses. There was an interesting back and forth about how the firmness of greens affects the speed and some speaker at a green super meeting suggesting that firmer can mean slower. Don't ask me to explain that.
Mostly I learned that with all things you need to have a passion about your craft if you have any chance to succeed. Both Charlie and Jim have that passion along with a respect for history.