The format of the meme necessitates a setup and a punchline, like any joke. The setup for the GGG meme is typically a description of a situation in which one is presented with an obvious course of action that is either manifestly dickish or criminal behavior, or simply an average, neutral act. The meme in question is obviously modelled after the former. The punchline of any good GGG is that he subverts that initial assessment by doing a kindness in place of whatever the reader assumed an average (or dickish) person would do. GGG can be a morality tale about successful interaction or just a demonstration of a good deed and it still follows this format. The punchline for this, and the reason GGG is titled good guy Greg within the format of the meme, is that he did not engage a passed out woman in an unwanted sexual situation. As stated, this does not make him a good guy. It is therefore an unsuccessful example of the GGG meme.

An alternate would be "Puts Drunk Girl To Bed / Guards Door For Remainder of Night". That is an example of being a Good Guy in this situation. Particularly when the absence of GGG instigates the Douchebag to assault the drunk girl within the story progression of the memes.

TL;DR: "Guards Door For Remainder of Night" is what a Good Guy Greg would do, not leaving the drunk girl to be assaulted by the Douchebag. Be a GGG!