Only after Fluffy's words did Andrew, Biacko, and the dragons recover and realize they had let their guard down, so they quickly reaffirmed their convictions. The spirit girl wasn't one to be so simple. First of all, she came barging into their territory and then attacked them most casually, and they, despite being demigods, didn't even notice.
Although the girl didn't seem to have any bad intentions, it doesn't change the fact that she had arrived unannounced, arbitrarily, and attacked them. Although very subtle, an attack is an attack.
What she had done was a kind of mental subversion. They didn't know how she did it, but when the spirit spoke, it was as if their hearts calmed, and it was right to let their guard down.
It must be understood that no matter how kind the spirit seemed and didn't express any bad intentions, the mere fact of having done what she did was already an offense, and if the situation and person were different, Andrew wouldn't hold back from attacking.
