I don't know, this seems like it was a pure CPU problem on good hardware. But anyway a developer who has 10 hour days and backlog stretching beyond the horizon

I don't know, this seems like it was a pure CPU problem on good hardware. But anyway a developer who has 10 hour days and backlog stretching beyond the horizon will not have idle time to go try things out. It needs to be someone's explicit job to go hunt down things like this. And given it was data-size dependent, I wouldn't be surprised this was not an issue at the start while someone who's job it was to look for this kind of issue was looking. And the issue appeared after they got retasked to something else. In fact maybe this is the only kind of issue that you end up with after all is said and done. Just like in WW2 they reinforced the parts of the fuselage on returning fighter craft without bullet holes, because if a bullet hit there, the craft would not return.