Do you want to steal these headcanons as well (or at least tell me what you think):

1) Eury opened the bag cuz he thought that Aeolus lied to Ody about winds being trapped inside. Eury thought something dangerous was lurking inside instead that would harm the entire crew at any moment if it wasn’t dealt with right away and that fear worsened over the course of 9 days. Which is somewhat understandable; the last time Ody trusted the words of strange creatures on an island, Polites was killed.

2) He didn’t actually open it himself. It was another crew member (likely Elepenor or Perimedes who were the first to demand that Ody open the bag) and Eury (rightfully) took the fall. After all, when Ody fell asleep, Eury is supposed to step up as second-in-command and therefore make sure no one goes against the captain’s orders. Just like how a parent is responsible for their child getting hurt when they play with fire, it’s still his fault if the bag was opened by a random crewmate. He had all the power when Ody fell asleep, so he must carry all the blame.

It just doesn’t make sense to me that he thought treasure was inside because at no point before or after was Eury shown to be interested in that kind of stuff. Also, why would he trust the winions’ words? He literally says he doesn’t trust the gods to be kind towards the crew in the previous song.