Leaving the school in any manner in which Kyron could be seen to be associated with Terri leaving, would place Terri at great risk of being caught, because of the extra people coming and going at the school that day. Even on a normal day, all it would have taken to be caught is just one person who happens to look out the window at just the right moment to see Kyron and Terri or Terri's vehicle associated with leaving together.
I do not believe that, if Terri planned this, she would have taken the risk. And I do believe that if Terri did this, it was definitely planned.
Based on the information we have right now, nobody saw Kyron leave the school. One child may have seen Terri leave the school, but it could have been that the child simply saw Terri walking in the direction of an exit, did not actually see her leave, but with a child's thinking, assumed she left at that time.
These things tell me that because of Terri's very noticeable long red hair, she left the school in disguise. It would be easy enough to slip into a restroom, tuck hair into a cap or wig, pull on another shirt or jacket, and switch shoes - perhaps from a more noticeable and feminine bright white, to a mundane, less-noticeable, and more masculine black or brown. Jeans could be left on since they are unisex.
A man leaving the school, hopping into a commonly seen white truck, and driving off, would be unlikely to stick in anyone's mind.
Two things would increase risk of being noticeable here, that need to be considered. Whereas there are rampant rumors that the baby was with a babysitter that day, I've seen nothing to confirm it. Terri may well have had the baby with her at the school. So she would have to get the baby out of the school as well.
Terri may have deliberately taken the baby to school that morning. Entering and being seen in the building as a woman, with long red hair, carrying a baby, would tend more to stick in people's minds. That is what people would be concentrating on, thinking about seeing Terri leave the school, or remaining in the school for a significant time after she said she left.
So, suppose while in the restroom (or a little-used basement room), before changing to a disguise as a man, Terri slips the baby something to make her groggy and quiet or sleep. Terri switches to her man disguise, the baby is now groggy, Terri puts the baby into a container of some sort, and a man walking across a parking lot and sliding a tote into the truck would likely not stick in anyone's mind. It's a common sight.
That same man returning into the school would also not be anything sticking out enough to stay in someone's memory. And likely any memory of that has faded, as people have been told over and over to concentrate on having seen Terri, a woman, with her very long and noticeable red hair.
Now we have Terri back in the school as a unnoticeable man. It's important to keep in mind that nobody saw Kyron leave the school. It's also important to keep in mind that if it was Terri who was the perp, that she had no reason for Kyron to leave the school alive. And why take that risk? If the perp was Terri, and this was premeditated, it makes much more sense for Terri to have harmed Kyron in the school. Perhaps in a basement. Then remove Kyron's body, as a man, in a wheeled container for the quickest and easiest exit possible.
A further benefit of this scenario for Terri, would be if someone did indeed see an unknown man leaving the school wheeling a container. It points the finger towards a stranger/SO perp.
Now where I got a bit stuck on this, is Terri, as a man, putting the container into the truck. Everything works up to this point, but a man putting, e.g., a large wheeled container into a truck may be noticeable, and even if the man can't be identified, the truck can. By license plate.
I quickly took care of the risk here though. Prior to arriving at the school that morning, all Terri had to do was pull over to a little-traveled out of the way place, and tell Kyron she had to check on something outside the truck - perhaps that she heard a noise or thought a tire might be going flat. At that point, she could quickly and easily smear something on the license plates to obscure part or all of the license #.
During the ride to school she could also easily remove other identifying items from the truck, such as if there was ordinarily something hanging from the rear view mirror. She could remove that, or even replace it with something else.
One other thing I haven't mentioned.
The questionnaire. It made little sense to me that LE asked only one simple Yes or No question about seeing Terri (or the truck) at the school. No questions about where seen or when seen or what she was doing. No questions about where the truck was seen, if it was moving, in what direction, if it was parked where it was parked. That made no sense. Until I came up with this theory, and went back to the questionnaire, and I noticed that there was a whole LOT of room given to write in info about a suspicious person or vehicle seen at the school. That made more sense to me. Take a look at the questionnaire and see what you think:
http://www.flashalertnewswire.net/i.../36184/061410.SchoolQuestionnaireadobe.hm.pdf