No manager worth his salt chooses a player based on who scores the most number of goals. No one does that.
CR7 says that he was running in front of the Fantrau guy after Fantrau had skipped the keeper. So, when Fantrau passed the ball to Ronaldo, Ronaldo would have been offside and the third goal would not have stood.
This Fantrau person rounds the keeper and passes to another player, and the manager picks the guy who tapped in the goal into an open net instead of the player who created that goal so skillfully? Say what now?
So, this Fantrau guy is as skillful as Ronaldo and he does not play football? Seriously? Some other manager would have picked him up if he was so darn good.
There is only this mention of Fantrau anywhere. And it's the same story in the same words. If Fantrau means so much to CR7, sure we would have heard more about him.
Ronaldo's move to Sporting in no way resembled what the story says. In 1997, Cristiano's club at the time C.D. Nacional owed Sporting €22,500. They didn't have the money so Rui Alves offered up Ronaldo if Sporting forgot the debt. Sporting weren't keen on the deal, paying that much for a 12 year old. So Nacional convinced a Sporting representative living in Madeira, Marques Freitas, to take him to the mainland and give Ronaldo a trial. There was no championship game, no manager from a big club, no 'the kid who scores the most comes to Sporting' fairy tale.