I have come across a couple bugs during my games and figured I'd list them here.

When playing a hive mind, the evacuation decision for tremor earth (or strong volcanism, sorry i forget which it was) required consumer goods. Which normally would have been fine, but this event fired before the galactic market was established, so the only way to get them was through console commands.

I also got the ice age event in a different game, and after it transformed I was able to terraform it back into a tropical world. However, after re-loading the game much later, the (final) event fired again and it became an arctic world again.

Hopefully this is useful.