If you have access to the internal statistics of the casino, then it is easy to prove the presence (or absence) of a connection. The behavior of one player does not mean anything, but if we have statistics about thousands, then this is the exact pattern of behavior. It is enough to look at their behavior on the market dump, on the pump and on the flat - then it will be clear how the market situation affects their behavior.
That kind of stats, the gambling site itself will know about the pattern.
But us, being the players, I don't think we can have clear understanding what's going on.
We can just speculate during this period, but we know that if you are a gambler, you will play no matter what the situation is.
But you may increase or decrease your spending depending on the availability of your funds.
Or if you have other things that you need to take care of. But mostly, gamblers will play in any kind of market.