ADHD isn't about not being able to focus its about not being able to control focus. Ie, when something catches my attention, I cannot let it go. I will start doing something, get really into it and feel like no time has passed only to discover I've been awake for 40+ hours and have 10 missed calls. It's rare to get that hyper focused on something but it does happen.
When it comes to planning, it's more likely to be a series of carefully laid plans that never get executed. If they do though, it's usually on a total whim at which point most of the planning goes out the window and it's largely make-things-up-as-I-go-along which is why the I think it's odd that the truck was circling. The area all day. That is not a sign of something happening on a whim and seems like it would have put a stop to things.
Totally different scenario but reminds me of something that happened when I was about 19. my boyfriend at the time had been making fun of my driving skills which irritated me enough that I had notes of practiced conversations detailing statistics that I'd researched etc to lecture him about why was wrong. Weeks went by and I never cared to tell him off for it. Then one day, I was having dinner with a friend something made me think of it, I jumped up, told my friend I'd be back in 30 minutes, I was going to the mall to catch him after work and tell him off. I got to the mall early,meh was busy with people some wandered around for awhile. I got back to my friend and I showed her the shoes I'd just bought. She asked what happened and I told her I got distracted by the sale rack and completely forgot why I went to the mall.
Again, totally different scenario but I hope it illustrates why I have trouble with the truck circling.
As for determination at all costs, I can see that happening to a degree. I think a major surprise factor like a little boy being unexpectedly present would kind of be like a splash of cold water/wake up call of 'this isn't what I'm here for, ABORT.'
