Do your characters have a simple test so they can tell what is magically sound or suspect? Nobody with any sense willingly upsets a powerful fairy, witch or wizard but can this happen accidentally? The person upset did not look like they were powerful and so on.
Can things not always being all they appear to be work to the advantage of your characters and, if so, how? Most in my magical world treat all magical beings carefully, mainly to ensure they do get to live another day. They see this as essential survival technique.