Perhaps it's crap, but something tells me the invisible random selector was set on Nidorina, thus when I turned off my GBA, not saving the first encounter, the imaginary dial was still set on Nidorina, or that Safari Zone area, and it was coincidental I saw a 2nd one.
Retracing only meant the number of resets of entering; exiting zones in your game-play session. You could do what you want & I chose to re-land near that old shiny frame; which worked.
And I wasn't trying to SPAM; was trying to help fellow shiny hunters.