Saying something is "baseless" is the equivalent of saying "there is no evidence of that," another Clintonesque claim of mock innoncence.
Notice that they do not actually say the didn't do it, simply "you can't prove it." Usually followed by the "XXX is working hard for the {insert children, American people, the unfortunate etc.)."
Plausible deniability, just in case someone turns into a stool pigeon.
"Not one shred of evidence" equals We shredded all the evidence". Or, "No controlling legal authority" equals "We got away with it when no one was looking".