Lies, damn lies, and politics as usual
I think it was actually a rather obvious setup, a kind of fishing expedition. Presumably none of the journalists was stupid enough to rise to the first bait, so the scammer tried to back off and pretend it was an honest mistake in the first email, presumably hoping that one of them would respond with with something like "But what was that secret? Maybe we can work out a deal..."
Anyway, if it had been a real gmail account that was hacked, it's trivially easy to find out who got the original messages. Gmail retains the sent posts unless you delete them.
However, the deeper point is the low credibility of modern politicians. Even when they know the truth, none of us peon voters can believe anything they say. That's why rumors have so much traction--they're usually as plausible as anything that the politicos say, and quite often the worst rumors turn out to be true, too. Like Dubya was *REALLY* concerned about the severity of Scooter's sentence and had no concern with covering the Dick Cheney's arse?