Unless...T and Kyron were not in the same group. Say the teacher was in the room and, as enough children arrived, sending them with the chaperone to see the exhibits. Since we know Kyron was there early, maybe he was in one of the first groups. It is possible that T and Kyron saw one another when T was on his way into the classroom and Kyron was already in a group (loosely) and on his way to see the cool electric exhibit.
So Kyron goes along with the rest of his group, T goes into the classroom and is added to a different group, and they don't cross paths.
If the groups were kind of loose - as in, we're going to 6th grade first and we walk sort of together but not really in a line or anything (it's only 5-6 kids and the hallways are likely crowded with other classes doing the same thing) and then they visit 6th grade. When it's time to switch rooms, the leader gathers them up and they go onto the next grade, and I would assume she would count each time. (But maybe not).
If the chaperone can't swear to when she last saw Kyron with the group, then T could be right. When the groups recollected in the classroom, that could be when the chaperone noticed him missing, and T would have been there.
That could also be why the timeline has been so hazy - maybe the chaperone isn't really sure (maybe she doesn't know all the kids very well) and the kids statements about the last time he was with the group conflict...well then LE would be very careful b/c of dealing with young kids AND not having a time they can confirm.
In the same way, if the teacher thought Kyron was in the bathroom, she may have looked for him or asked another teacher to look for him when he didn't return promptly. All it would take is another teacher saying, "I saw him with Terri...maybe they left. Half my class is gone!" or the teacher wondering if she misunderstood about the appointment and assuming that she must have.
It is not necessary that any of these statements are contradictory. We have not seen the complete statements - only bits and pieces.
