I can say there was a clear violation of the sportsbook ToU made by the OP but after many conversations with the third-party risk management team, we decided not to comply with their decision and fixed the situation at our own expense. In the future, I hope the OP will read the terms of the sites he is using before making these types of accusations.
If there was a clear violation term of usage, there is no reason to pay players who violated the conditions. I assume you have paid this user; as you said, you guys fixed the situation at your own expense. The community cannot force you to pay someone who violates the rules. If a player does not accept the rules, he should not play on that platform.
For clarity, can you at least reveal whether this user gets paid? Sometimes accusers leave the thread silently, and the community never knows what happened. Let's say he was paid, but the thread remains unsolved. Opposite is possible as well.