Which of these sentences lacks parallel structure?

Not only did Zach get a ticket for running a red light, but he also got a ticket for speeding.
I completed the assignment by rereading the chapter, took detailed notes, creating an outline, and then I studied all of it.
He doesn't know yet whether he will go to court to fight the ticket or if he will simply pay it.
If Zach ever gets to drive the car again, he promises he will both watch his speed and stop at red lights.