What if Giulia didn't come during the fight scene?

In Luca, when Alberto takes charge of Lucas bike down the hill and goes crashing down, we are shown a fight with Alberto and Luca, just before Giulia does arrive at the shore, and shortly after knowing Albertos secret, Alberto pinned Luca to the floor with his fist in the air. Watching this, I honestly thought he was going to punch him, so this is my view of "What if Giulia didn't come when she did during the fight scene" Any suggestions for further chapters commented by followers will be taken note of. By the way, the first section is taken from the movie because Giulia couldn't have changed the first bit. Thanks!