I'm SO not into conspiracy theories, but this is one hell of a bungle. First of all this is an FBI case if ever there was one. Metro commenting seems bizarre. Essentially, as a character in The Fugitive once said, "Care to change your b***s**** story?"
The whole news sequence makes no sense. On the breaking story we knew: ricin for sure; a guy who was fine; no terror suspected. How do you get from that to twelve hours later "Whoops, we've got a comatose human, a dead dog, and a guy who is a friend or relative."? The sequence is backward.
It should have been. Cops called. Body goes in ambulance, dogs alive and dead are processed by animal control. Breaking news of crtical patient and dead dog. Unconfirmed reports that white powder that authorities have reason to believe might be the deadly poison ricin are being followed up by our news team.
Unless the mysterious friend or relative bounced up to the desk clerk and said, "Hey does this look like real ricin to you?" Something's not right with this story.