I suspect that most of us have upset the wildlife at some point in the game. While in the wild, I usually stay in peace mode until I can attack any enemies without attacking any snails, frogs, tibars, etc...
my former post was referring to this sentence of yours.
I had no trouble in-game with snails (were/remained friendly). But this Uebersnail was in the after-game Battlefields and attacked me, was as hostile as all other living creatures there.