Pretending that she has to go to the toilet, Lorelai sneaks upstairs and begins making her escape through the window when Richard comes in, looking for her on Emily’s instructions. Poor Lorelai can’t even go to the toilet without her mother sending a search party to find her, although in this case Emily’s instincts were actually correct.
It looks bad, because to Richard and Emily, teenage Lorelai sneaking out the window was Lorelai going to meet boys, get drunk, get into trouble, and basically ruin her life. There’s an acknowledgement, even from Lorelai herself, that on some level she hasn’t really grown up. She can’t have an adult conversation with her parents, or make up a believable excuse to leave early – her immediate response is to revert to her teenage self, and sneak out without thinking about it too much.
To his credit, Richard listens to everything Lorelai has to say, and simply calls out to Emily that he couldn’t find Lorelai. They don’t have a close relationship, and have recently argued, but they do share one thing: a great dislike of the odious Chase Bradford. Richard cannot escape himself, but he at least allows Lorelai to, and for that she must feel a genuine gratitude.