While it is rather annoying that he just ignored her, there could be a simple explanation for that, for example imagine its the middle of the night, your in a dark forest, (cant remember if he had already seen the entrace or not) and you hear a loud random scream from a voice you cannot recognize, sure it would make sense to go after her, but at the same time you have no idea what you might get into
he first heard the girl scream and started looking for her and then he found the door. i mean if he already committed to look for the girl then at least try before giving up. he just forgets about the girl and he has a "meh" reaction after he found the door. but after playing the story a little bit further the girl screaming mightve been an attempt to lure us to the door