Why didn't he remove himself from the chat? He could've said, "I think I'm here by mistake, I'll pop out," but no. He used the mistake to journalistic advantage instead of using journalistic integrity.
"I can't believe what we're discussing happened nine years ago...with really more questions than answers after all this time... we've had four different investigations already." - George Papadopoulos details the years of investigations into Clapper, Comey, and Brennan.