Not sure why you think there's more to the story. It's extremely common for "unreleased" versions of various apps/services to have bottlenecks that the production-ready versions would not. That's typically why they're "unreleased".
If this isn't a service-overload issue, I'm having a hard time imagining what kind of problems this unreleased Android version could have caused.
This is exactly why companies like to have tight control of the roll-out of new products. They want to find these types of bottle-necks and glitches in rather controlled environments.
But there was no such rollout. An unreleased version leaked.