The opening post has some information proving that Trêvoid was talking to bchannel.
Trêvoid said they 'd rather keep the transaction amount secret, but if they wanted to create a flag, they 'd need to provide some more info, like: (a) transaction details, (b) deal details, (c) more specific screenshots about the transactions.
It's not mandatory to include these details to create the flag, but it's important to be as detailed as possible for other users to support (or not support) the flag.