In that case it just sounds like the alien simple was looking for an excuse to attack humans. What else could humans do in this situation, it's not like they can talk to the monster and ask it to leave, attack is the logical thing to do...

It's always better not to put pressure on yourself, life already has enough pressures as it is, and fanfiction and fandoms in general are supposed to be just a fun way to relax, and not an obligation.

That is rather convenient for humans, I guess, very nice of aliens to think about that :)