that is to say, when making a statement is personally detrimental to someone, and they make it anyway, that statement should generally be given a higher degree of belief than one that is self-interested.
so in other words, if the CIA denies that they did something bad, you don't necessarily believe that straightaway, because of course they would say that. On the other hand if they do admit they did something bad, then it's OK to believe them in that instance even if they've lied in other instances.
Now of course - in the specific case of the CIA they are a government apparatus, not an independent actor, so the fact that they say (eg) Russia did a bad thing isn't necessarily against their interest, it is in their interest for the US Government to look good and truthful. But as a general rule, it's important to look at the interests in a specific instance to determine rather than just assuming that because an actor lied once that everything they say is suspect.
https://definitions.uslegal.com/a/admission-against-interest...
https://en.wikipedia.org/wiki/Declaration_against_interest
that is to say, when making a statement is personally detrimental to someone, and they make it anyway, that statement should generally be given a higher degree of belief than one that is self-interested.
so in other words, if the CIA denies that they did something bad, you don't necessarily believe that straightaway, because of course they would say that. On the other hand if they do admit they did something bad, then it's OK to believe them in that instance even if they've lied in other instances.
Now of course - in the specific case of the CIA they are a government apparatus, not an independent actor, so the fact that they say (eg) Russia did a bad thing isn't necessarily against their interest, it is in their interest for the US Government to look good and truthful. But as a general rule, it's important to look at the interests in a specific instance to determine rather than just assuming that because an actor lied once that everything they say is suspect.