McMaster probably spoke the truth. But you guys are missing the point. It was never said that Trump revealed the sources, only that there is fear that Russia could discern the sources based on what they know.
Stop and think about that though.
What would Russia do with that kind of intelligence? The source [probably an individual] operates [probably lol] in Syria. And this individual has the most to fear from whom?
ISIS terrorists.
So, are the Russians going to communicate the name and location of this individual to ISIS? I can conceive of no circumstance where Russia would be motivated to do such a thing. Even if they used the asset, it would be against our common enemy, ISIS.
But maybe you can think of something.
Assuming, the anonymous sources are accurate and Trump unwittingly outted an asset and/or their location---that intelligence has little value to the Russians. The 'big deal' would be that Trump unwittingly revealed it.
Granted, not something you want to happen, but this story will be replaced by the next 'big deal' by this time next week.
In fact, I would wager that sort of thing has went on before [it would be interesting to know how many sources, that the Russians actually value, were exposed on Hillary's server] but things are different with Trump. There are anonymous people that are actively working against him.
That much is clear. The amount of leaking is unprecedented.