When the song came out, almost all phones would have been rotary dial, so this is probably just coincidental.
8 dit-dit-dit-dit-dit-dit-dit-dit 6 dit-dit-dit-dit-dit-dit 7 dit-dit-dit-dit-dit....
ON the other hand, touch tones were invented in the 60's, so it's possible that they had access to the tech to touch dial at that time.