Personally I don't think James is a crook
So holding hostage the property of hundreds of innocent bystanders -not to mention all the rest he has done- is fine for you?
Then you see no problem even in bank robberies I guess.
I have not yet confirmed that this is the reason why he has not released the information to the issuers and I find it unlikely. As it's probably not the issuers that have the extra BTC but the asset holders. In which case a personal boycott of each person which did not send back the double payment would be more efficient.
I will call James and have a chat with him I am sure that he's not holding anyone hostage over this and that it can be explained.
//DeaDTerra