This is definitely a mainstream media.


В «Шустер Live» журналист «Sunday Times» рассказал правду об ополченцах ДНР

Look at the histeric that started at 4:32. "Savik, let's stop this ... propaganda. I understand that he saw that with his own eyes but to spread this BS to whole Ukrain it's just a shame...." (said in Ukrainian)
And all others were like that.
Finally they came to a conclusion that he's either Putin's agent or just crazy

Here's brief stranscript of that show В «Шустер Live» журналист «Sunday Times» рассказал правду об ополченцах ДН

BTW Mark Franchetti speaks russian with heavy accent but with amazing fluency and knowlege of slang