Please someone tell me if it is enough to put some lawyers to work, or if it would be just a waste of time. Thanks!
First action is to contact any form of customer support of the said site and tell them what happened and show them what you've got during your observation. Wait for them to respond back, see if they will help you or advise you something else. If they insisting that there is no cheating happening, gather more information. If they stopped cheating on you, then it's up to you if you want to pursue it for other users or just continue playing. Legal works are kind of expensive nowadays, and not worth the hassle if we are talking losses of a 50 to 100 bucks. Just go to another site and use anonymous accounts and bad mouth the said site.
He should do that first, to contact their support, to save that conversation and then to come here and share the entire story, the name of the site, screenshots of his bet, hash, entire talk with support. That would be something, like this it's just one more newbie complaining about losing his money in casino... one more thing support that claim, except his first opening post we didn't hear anything from him after.
It's true, there's no point for legal actions for some small amounts of money. But he can reveal the site to others, and if he can prove his claims that casino can lose some players!