B ut the tweet immediately raised questions about when Trump knew about Flynn’s lying.
Except it was a tweet. Even if an obstruction case were possible, Trump could simply say that his tweet was based on current knowledge. i.e. he fired Flynn for lying to the VP and we’ve since learned that he lied to the FBI. At least he’s pleading guilty to that particular parking ticket.
Quibbling over the time is not going to cut it. Better to go with Dowd’s perfectly sound legal theory.
There must be some concern if the attorney is falling on the grenade.
Even if it would have been a case of obstruction of justice for President Trump to fire Comey to stop an investigation, a prosecutor can only make this case by proving the state of Trump's mind when he fired Comey. The prosecutor can't possibly do this without first interviewing Trump himself.