they... well, the lead singer, were huge metalheads back in the day.
they are probably quoting the metallica song for humor if it is in fact the same.
I haven't heard the song in a bit, so I'm not recalling it - I saw a clip of the video though and it looked funny.
I just bought the old alsum (not pinkerton) again on cd, I used to have it on tape and lost it somewhere... just as well since I don't own a tape player anymore.