They actually did have beta tests, which is what makes this so puzzling. I'm pretty sure Geoff Burrows from NAG Magazine was in on the beta, but I might be mistaking him for someone else.
As far as I know, each beta session was limited to one hour, making it difficult to identify issues like this which only show themselves after a few hours of play. If they had increased the allowed time in the beta it probably would have been ironed out before release.