Further down the article:

> After a few minutes, he found me coming through the security line, and sure enough, my computer was not with my bags when I retrieved my belongings. Moving further back in time, we watched as a TSA agent pulled my computer off of the belt as soon as it came out of the machine—there is an area where agents can remove things from the belt before passengers have access to belongings. He moved my computer to a holding area immediately behind the x-ray machine. And then, we watched as the computer was inspected, after which it was handed back… to a random woman. The woman took my computer and left the security area.

He completely forgot his laptop, moved away from the security check and only later figured out he was missing his laptop.

With hundreds of people moving through those checkpoints, I do not blame the TSA agents for handing stuff out to completely random people.

He forgot his laptop, because it wasn't on the belt when he came out of the scanner. They gave it away before he had a chance to forget it. The couple of minutes it took him to realise that he didn't actually all of his stuff off the belt (even though, he did, since the laptop wasn't there any more) wouldn't have made a difference since somebody else has taken it beforehand anyway.

Especially if you're used to being able to leave your laptop in your bag - you fall back to routine very easily. I want to fault him for walking off and leaving it, but I can also imagine myself easily doing the same.