I would probably react the way DJ promised! That is I would tweet the simple response that I didn't have a source at the club. I would value my ticket and my dad's business more than valuing my own ego over a parody account on twitter.
I am not sure what else Chang could have done in this case, I imagine he didn't believe that DJ did not have a source and by getting him to at least 'come clean' on twitter would stop people from thinking that he did and thus creating twitter frenzy over potential targets. I am not sure that the effects Chang talks about, i.e. Roma and Borini's fee were genuine, but obviously there is/was a problem at the club with regards to leaks, and he suspected DJ was a part of it, so what else could he do but to put some pressure on him?
Exposing Chang for what he is does actually damage the club, you only have to read what people are saying about to understand this. Yes it will blow over, but at the moment by association it is Liverpool FC who are at the centre of the scandal!
Anyway, maybe I will talk about the footie as well at some point, before that you can draw as many conclusions as you want. However, you look foolish when you call someone an American based on those conclusions...it just goes to show that not everything is as it seems, maybe that is the case with DJ too?