Muted fill?

I haven't played any metal in some time, but today I decided to tackle a song or two. Despite expectations, I was going fine - until I got to the second half of "Peace Sells" by Megadeth. I've been playing that single-note riff that comes in after Dave says, "Can you put a price on peace?". I may be mistaken, but I think it requires a muted fill on the A-string after the second E note. Is this so, or is it just my imagination?