Somehow the context of the song hasn't been shared on the thread yet:
Whispered goodbye as she got on a plane
Never to return again
...
This love has taken its toll on me
She said goodbye too many times before
And her heart is breaking in front of me
And I have no choice 'cause I won't say goodbye anymore
Clearly "before" is needed to rhyme with "anymore". Also it is referencing the times she said "goodbye" before she said it this last time when she got on the plane.
There's no audible difference between signing "she's said" and "she said", the s's blend together. Any possible difference would be entirely obscured by stylistic choices.
Even vocalizing normally the difference is hard to tell. Try saying "She said I love you" vs "She's said I love you" – unless you make a point to completely stop in between words there's basically zero distinction.