That's typically how a game provider works. They give the API for the platform and rest are handled by the casino itself.

About above other claims, I would like to ask how are your sure that it was owlgames (I might missed some leads).

I would also ask owlgames how far they can access of a casino who they provide their software. It should be limited only to provide information once a casino ask about a specific bet or bet transaction issue. Have in mind that a provider can also access customers information too including their browsers information, IP and such things.