I saw this posted on rawk - they regard Harris to be some journalistic powerhouse - and, although I won't bother linking his tweet, he states before it:
"I've spoken to multiple MCFC / CFG employees & former employees since 2014 who are not comfortable with City's behaviour. I have zero need to protect this person's anonymity but will anyway. If you want to ID yourself and try to justify this, then please do. You know who you are."
If I have Stefan's Twitter correct - this must have been referencing him because Slbsn then responds:
"Sad move to attempt to bully or seek to embarrass me by tweeting my pure speculation at what a given Der Speigel email may mean when we were very periodically on DM years ago.I hope you have better sources/whistleblowers than me as I was never an employee, have no access to any confidential information at all and last worked for the club as a financial (not legal) adviser (not an employee as you claim) in 2007. Everything I say is opinion, analysis or speculation from the outside. So whatever you think you get by making this attack I think you will be sadly disappointed. I certainly have no need to justify anything. You are the one that claims to have the inside sources. You’ve just blown your own credibility if you consider me a source."