"Maybe someone around here gave him lessons"
Huh? Who? Who took the mentally out-to-lunch, faux-catatonic, murderous child for a day out and gave him driving lessons? And why? And how?
Even as a kid this line bugged me. Ironically, the loathed Thorne angle of part 6 actually fixes this. However unintentional it may be, the revelation that Dr. Wyn is the mastermind behind it all provides a reason why and answers the "who?" with one of the few (only?) people who could realistically sneak off with a patient.
Now if only someone could fix Annie's brainfart: "What's the pumpkin for?"
My hope is there is an extended version in the vaults where Laurie just looks at her dead-pan and says "It's Halloween, stupid." Then Annie says "I know, but I thought maybe he was your date."