Arrington is smart, a lawyer himself, and already know he is headed straight to the witness stand. Thanks for blowing this whistle Mike. That's the TC we like.
I don't know if witnessing a table full of people go silent when he turns up proves anything, and the rest is all info that would put his source on the stand, not him.
If you read the full post, take in account that he was present and saw who was there, and assume he has not chosen to reveal everything about the sources through TC at this time (that's highly understandable - protecting his sources and only disclosing what he feels is verifiable), there is definitely a lot here and absolutely enough for a climb to the witness stand!