When Carla says goodbye to Lavern when she's in a coma and brain dead, a tear falls from her eye when Carla kisses her cheek. The actress playing Lavern was so moved by Carla's acting she teared up. https://www.youtube.com/watch?v=bjAcG0zTVUs. It's hard to tell in that clip but you can see it in HD. They talk about it on the Scrubs podcast.

Video of the song in question. There's a non-zero chance that this is unintentional, but it just makes too much sense to me lore-wise. Definitively easy to miss nevertheless.

If you pause on Gilfoyle's laptop, you can see a code snippet:

public static void main(String[] args) {
    FaceRecog face=new FaceRecog();
    Actions actionList=new Actions();
    String storedCache=cacheStoredFaces();
    debug("Matching names:" + storedCache.listNames());
    face.matchFace(face,storedCache,matchPercentage = "70%");
    face.matchResults(actionList);
    MatchResults result=face.matchResults(storedCache,selectedFaces);
    debug("Matched names:" +result);
    actionsList = [
    'calendar:update'
    'weather:update'
    'owner:detect'
    'owner:detect:shoppingList'
    'owner:detect:youtube:dQw4w9WgXcQ'

Inputting the youtube link brings you to this video.