Continuity mistake: In the scenes where Johnny and Baby have to break into the car, when Johnny looks in to find his keys, it's raining, when he turns to grab the post to break the window, the sun is up and the ground is dry, then when he turns back to actually break the window, it's raining again.
Continuity mistake: In the last dance scene, notice the part before the performance, where everything goes dark and the spotlight shines on Baby. You'll see Johnny take off his coat. Then the camera goes back to Johnny offstage taking off his coat again.
Factual error: Notice Baby's white Keds shoes with the blue emblem on the back of them. That specific style of Keds didn't come out until the 80s.
Revealing mistake: In the scene when Johnny realises his keys are locked in his car and goes to kick the pole out of the ground there is a light on top of the pole. Where are the wires for the light?
Continuity mistake: When Lisa goes to see Robbie and catches him in the act, there's a towel on the doorknob when she opens the door, but it's gone when she pulls the door closed.
Revealing mistake: When Johnny and Baby are cruising back from their performance in the black 57 Chev, the shift is in "park" position.
Continuity mistake: In the breakfast scene, the baby's hair starts off styled, then is teased up haphazardly, then is styled again.
Continuity mistake: When Baby is getting dressed for the talent show, she is rolling down individual stockings, when she starts dancing with Johnny, there are no garters showing, even though her dress goes all the way up.
Continuity mistake: When the movie begins and Baby introduces herself, the position of her left hand holding the book changes between shots.
Other mistake: When Johnny breaks his car window, he is getting soaked but Baby is completely dry - her coat never gets wet.
Audio problem: During the "Hula Hana" scene, you can tell the little girl with the ukelele is only mimicking playing. A chord is heard being played in a staccato fashion, but the girl is merely rubbing her thumb against the body, and maybe striking the lowest string, while not fretting any of the strings with her left hand. Playing staccato on open strings would require you to use one of your hands to stop the open strings from ringing.
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.