Mothers behavior was unrealistic

Like movie tried to tell us that she was glad that Dexter had a real friend and went outside to enjoy his time left and be happy boy. I get that.

Bit it was very obvious that Erik is a bad influence and just dangerous. From the moment he gave her son poisonous leaves that almost killed him - any concerned mother would kick Erik out and forbid your kid to hang out with him. Because Erik is reckless and stupid.

Then he took Dexter who seemed completely fine on a roadtrip and few days later he calls that Dexter is very sick, kid goes to hospital and dies. And she is like: "Oh well, it was about to happen anyway".

Movie should have at least try to pretend it wasnt Eriks direct fault. Like show how Dexter went to hospital, got better and return healthy home. And then got worse and died next year or something for unrelated reasons.