That is interesting. I've had to run building energy simulations where I spent a lot of time running through similar scenarios while trying to figure out set points for an automated natural ventilation system. It went pretty much exactly as you describe, if you don't catch that heat gain at the right moment, the interior temperatures can get caught increase to a point where opening windows won't exhaust the heat anymore. Since I was working on a completely passively ventilated building at the time, that meant the heat gain would remain, and if there would be a gradual positive feedback loop over the course of a couple of days meaning everyday the interior temperature would get a hotter.
On hindsight, I wish I'd tracked the data for you :)
We were fortunate enough last year to still have quite cool nights; even if I screwed it up, opening the windows at both ends of the house would cool the place down quite well over night. The only really awkward part was when my wife would come home at 6pm, and she'd be uncomfortably warm until it got dark (which wasn't until 10:30pm or so).
