So, Julie and Fern would be totally screwed as well....
After watching this again for the first time in years, I sorta realized that Julie and Fern would also be screwed right along with Marcy and Courtney.
If Julie had found the photo she was looking for, it still would have been her word against Courtney's. So, I don't know why she and Zach thought that would clear anything up. In fact, it would look worse on her end since she'd have been the one to bring the photo to the police, and they'd have definitely questioned why she had it and Courtney didn't.
And, yeah, they had the recording of Courtney admitting to the accident, but it would still be her word against Julie's. If Julie is willing to admit her part in the whole thing to ease her conscience (which is evident when Julie is looking for the photo... Zach tells her she has to tell someone because it's the right thing to do, she agrees) then she'd still have to admit her part when the truth came out via the recording of Courtney.
Fern lied for a makeover, and that would be bound to come out...
So, yeah, they'd all be screwed.
I don't really get why Julie and Zach seem so pleased, like their relationship will be wonderful, and they'll get to be together forever now. It's going to be a little difficult to maintain a relationship when Julie is behind bars.