OK Here's how I'd handle a similar thing. I'm downtown dealing with the contractors for the building remodel we are doing for our rental building. I get a phone call from the vet who needs me to check something on a ewe with mastitis we have been treating and call her back that day. I write the note on what I need to check and the vet's mobile phone number in my little spiral bound notebook I use as a capture device. When I get home and go inside to drop purse and receipts and other paperwork off in my desk inbox one of the first things I do is pull out my notebook to add the stuff in it to my inbox. I always read the notes as I put them in because often my scribbles are somewhat illegible or cryptic and I can add more info to them as I do that if needed. So I pull off the 4-5 pages of notes I took on that trip and read them as I put the papers in my paper inbox. Most are for things that are not critical so I just add whatever additional words I need to be sure I will understand my note to the paper and toss into my inbox. However, this item is critical. I process it immediately by adding the next action of "Go catch Alaine and check the consistency of the fluid from the affected half of the udder and call Dr. X with results at (mobile phone number)" to the context "outside with help" in the "Deal with 866 Alaine's Mastitis" project and put a due date and time of when I got the phone call. That makes it overdue and so highlighted red so I see it easily. This information is on my iPod touch in Omnifocus and I carry it with me all the time. The data are also on my desktop mac. While my husband and I are getting some water and deciding what to do next I let him know I have an action I need his help with that I need to do today. He's got something he has to do before that so we agree that I'll get the crooks and jug panels and meet at the pasture where the ewe is in 30 minutes. We do, I get the check done and while we still have the ewe caught I call the vet on my mobile phone from the pasture. That way if the vet needs any additional info while I am looking at the sheep I can get it without the stress of catching her up again. I take a few more notes of stuff and we let the sheep go.
So in my case I do some almost pre-processing regularly at logical breaks in my routine and when I see something coming in to in that needs a fast response I go ahead and do the full processing at that time.
In your case I'd process the notes when I reached my destination and discover the issue and deal with it.
Oogie McGuire - Mac, iPhone & Omnifocus
OogieM on Twitter
Paonia, CO USA