Other mistake: In the scene were Patrick breaks the car window, when he walks to his seat you can see a point of red light (like a laser) on his back. (00:40:45)
Other mistake: Under the Gazebo when Penny is giving a lesson to the group, the opening shot is zoomed in on people's feet. The 5th person is a lady wearing red kitten heels. When the picture zooms out to show the entire group, the lady with the red heels is gone. (00:04:40)
Other mistake: When Johnny breaks his car window, he is getting soaked but Baby is completely dry - her coat never gets wet.
Answer: It would be improper to cause a scene, plus Robbie admitted to getting Penny pregnant and insulting her, especially it's what made get an abortion and medical complications.