Maybe I am being a tad simple here BUT:

There was a robbery of around $20k or so.
A dye pack exploded marking the bills.
Consumers are now getting the bills from ATM's

Simple me would think that LESS THAN AN HOUR LATER OR SO (or 1st thing in the AM in this case) some sort of notification would be sent out warning banks and businesses (easier for banks obviously) to be on the look out for said bills.

Somehow the bills ended up in at least one bank. No excuse for that UNLESS there was an involvement on the bank(s) part. I'm sure Joe Crook didn't show up with a single $20 but rather a decent quantity since they showed up in quantity in ATM's. See red dye...save the video of the crook...catch the crook.

..and...I didn't know the bills were not legal ("being refused", "stuck with") after being exposed. The marked bills are part of a trail and should help determine where they came from AND should be exchanged. How can the bank refuse to exchange bills received from THEIR ATM?

..and what if the money was recovered intact after the dye exploded? Is the casino out the $20k either way? Somehow I doubt it.

As was mentioned by others, there is NO WAY this money should have been turned over to consumers by a bank. It kinda defeats the whole process of the dye pack.

Rant over...