There are a number of errors during Eliot's fight in the recording studio as the story flips back and forth. The most glaring being when Eliot hits the goon with the drumsticks and the next shot that comes back to Eliot shows him just bringing the drumsticks into the fight.
"In the song that is the centerpiece of this episode, there is a flaw in the imagery. A new moon is completely dark, so it can never shine in a window." ... This is poetic license on the part of the lyricist, illustrating something that is felt rather than seen, just like the people in the song are a million miles apart/right next to you.
When Kirkwood's henchman looks at Sophie's cell phone and calls Worcester Studios, Nate mispronounces the studio's name. Worcester is a city in Western Massachusetts and is pronounced wooster, or wuh-stir, not 'war-chester'.
If Hardison put the girl's master tape into the machine and it was still there when they left the studio, how was he playing "Kirkwood's" tapes in between?