It's not 'magic' to me either, it's logic. If TH had 'so little time' that she could have been caught...so could someone else. They too could have been 'caught in the act' leaving with a child who was not their own and the same timespan would apply to them...why would it not?
LE has said that TH is their last known witness to have seen Kryon, which means that no one else at the school saw him after 8:45ish. Thus, if TH did not take him from the school, whoever did so did so almost as soon as she last saw him...not between 9 and 10.
All it took was a few minutes to get Kyron out of that school, and those few minutes seem to have happened around 8:45. And if the atmosphere were so chaotic that no one would have noticed a stranger taking Kyron...then no one would have noticed TH taking him.
I'm not saying TH took him or didn't...I'm just saying if it's risky for TH to take him and not be 'caught' (caught taking your own child???) then it's just as or MORE risky for someone else to take them. And if it's odd (per other opinions floating around the 'net) that no one saw TH leave with Kyron then it's doubly odd that no one witnessed him leaving with someone he should not have been with...IMO.
There are always exceptions to the rule, but with regard to this case when discussing luck or it being risky or what have you, for me it boils down to this --
Usually, when a mother kills her child or children, there is no inherent risk of being caught in terms of how she does it. Usually, it's done privately, and the risk is taken later when she attempts to cover it up. However, pedophiles thrive on the risk of the actual act -- Amber Dubois, Chelsea King, Danielle van Dam, Elizabeth Smart, all the way back to Adam Walsh, were all taken from public places or inside their homes at just the moment the predator knew he could get away with it. It wasn't luck; sadly, it was skill.
For a pedophile, what greater risk, what greater thrill than to take a child from a school? The Science Fair was advertised on the board outside the school, the community knew when and where and what time it was taking place.