Originally Posted by SATTSO

Ah, well I've seen that happen too, and for various reasons. One, a passenger does not fully push in their bin as I described above, and the next passenger gets frustrated with the bin blocking them. Most people just push it in. I've seen it happen a few times where the following passenger takes the left behind bin and puts it through another lane; some sort of revenge, I guess. Two, sort of same story, but a TSO does it (some TSOs are asses, we know this). Three, a passenger behind moves to another lane and a TSO helps by grabbing their bins and grabs another passengers by mistake and sends it through another lane (guilty of this myself). Four, of course possible theft.

There is no way to know if it was an attempt at theft with the info you provided.