Ways for druids to bring back the dead

[Darg]

"Sorry, I don't have raise dead prepared. I didn't think I'd need it, and I don't have the material components anyway."

This wouldn't work on its own. Raise dead gives you days of time to prepare and cast the spell.

Then again, if players are 9th level they likely have access to teleport which means getting to another cleric shouldn't be an issue. Which actually plays really well with this suggestion:

Just say he worships some god that treats death as final, so he's not allowed to bring back the dead. A nature god who views death as part of a natural cycle, for example, may view raising the dead as an affront to that.