Why did you remove the spoiler tag from the comment you're replying to? It defeats the whole purpose of the original poster's marking.It was completely unintentional. The FMC did not know that there was a dragon living there. That being said, she never came clean about it until later when his mind has already been made up that she tried to kill him.
That being said, why is that these guys are always so quick to banish/expel the friend but never delegate them to another part of the team? She definitely isn't evil but she is definitely not nice to the MC during his lowest moments.
As we saw in this chapter, she gets on him for being useless and getting in the way. It ultimately turns out that she would cry herself to sleep at night for her behavior towards the MC only to berate him again the next day. Rinse and repeat.
What hurts about this is that later, the FMC's clan starts recruiting people of the same rank the MC was when he was kicked out of the team and helps them train and get stronger.