Remember when everyone here said that casinos are just taking your money when a glitch happens, but never pay up for it?
I've overheard a talk today on this topic between some of my colleagues and their conclusion was that it's probably a commercial stunt.
The loss was far from unbearable and it helps their image much more than any advertisement. They'll earn that money back in no time and they benefit now from this.
Imho it doesn't matter.
If it was truly an error and a decision to pay, it was a lucky error and a smart decision.