Sending an email like this to Arrington and telling him he might find it 'interesting' amounts to saying 'print this'. Further, all involved parties in a story do not have to agree before it's published. If an employee is harassed by her manager, does the NYT seek the manager's permission before publishing the story? I have indulged in TC-bashing on several previous occasions, but I don't think expecting Arrington to keep this stuff confidential is reasonable under the circumstances. If anyone's to blame, it's Goodrich.
And as far as Arrington's reputation is concerned, I don't think it's going to take a hit - he's a 'journalist' and he has to make a living =) It might actually save him some trouble because now people are going to think twice before sending him 'interesting' crap.