I'm wondering the same thing.
It seems like he's sidestepping the question so-far. If this follows the same pattern of the WH exposing so-called fake news in the past, they'll circle the wagons, try to find the leak, if/when they can't, they'll deny deny deny, throw in a few "fake news" indictments for safe measure, then wait for the next Tweet or leak.
Does anyone really believe Tillerson wouldn't, hasn't, or won't call Trump a moron?
It seems like a group as imaginative as the media is, at-least according to Trump, would come up with a slightly more interesting or damaging lie (sic) than this.