I get that, but unless the service makes it known ahead of time that clients won't get details as to why the conclusion was made, how does that client know whether they might want to take their business elsewhere?I think it all depends on the policies of the particular service. If one service is OK with giving out that information, fine. If the second has a hard fast rule against it, that's fine also. It's the company's prerogative to set their own policy. If customers like or dislike those policies, they have the option to go elsewhere.
I know NOW that Fakespotters won't disclose how they came to a conclusion and as such, can now choose not to use them, but that should be disclosed on their site so people like Lindsay know whether they're comfortable with using them.