Then you have never really sifted through the pages of this forum to see that even huge casinos are trying to make the winners feel like shit in order for the winners to not claim their winnings. Even legitimate, land-based casinos are trying to prevent big wins from happening, just like
this one wherein the casino tried to offer a steak dinner to a woman that 'won' $43 million jackpot on a slot machine. The casino and even the New York Gambling Board mentioned that the machine malfunctioned, but it's kind of a joke seeing that the machine only becomes broken when big wins happen.
Casinos will try their best to not give out big wins, and if you have never seen or heard of one, then you must not be involved that much in gambling for you to not know this.
The case you stated above seems not an online casino, it is an offline casino. And the case isn't the limitation of a certain country to win big price, but the casino refused to give the price to the gambler. It is not the same case (topic) that is described by the OP, it is a different case, dude. For the case you stated above, surely I already heard the same cases many times.
By the way, if there are online casinos that always try to not give the price to the gambler, I believe all gamblers will leave the casinos and will judge "scam" for the casino. The casinos won't survive a long time, a bad reputation will make the casinos to have no users.
I guess what you are trying to explain here above is quite different from what "O.P" meant as stated in the thread, because those are two different concept altogether. The woman who won this $43million took place on a land base casino 4yrs ago, of which the casino claimed that the slot machine had a malfunction, and for that, the winning won't be paid.
While, O.P is asking, Do online casinos disadvantage some locations from winning big? Which the answer is "NO" because no legally registered online casino will disadvantage any region from winning big, but can only restrict certain regions base on reasons best known for them.
You are right. He misunderstood the topic.