I've always thought of Fonzi of being essentially a honest but misguided person determined to capture his white whale ("Let faith oust fact; let fancy oust memory; I look deep down and do believe") but this is pretty damning.
They so much believe in their cause that they lose all bearing. Is that a defense? Or an excuse?
Side question: In your Kelly link he says that Phillips lied to the HSCA and that they were preparing to indict him for perjury. Is this the Tanenbaum issue about the tapes in MC being delivered? Phillips said they were erased and no tapes were delivered. Tanenbaum quotes that mistaken Hoover memo (he got from Mark Lane) saying they were. Thus the perjury allegation.
Other than the Phillips-Veciana confrontation, which was Fonzi's word against Phillips, I've never been able to pinpoint exactly what anyone thinks Phillips lied about. He was mistaken about some of his actions in Mexico City (that is coming in Chapter 26), that is true. But the purpose of his second testimony was to clarify those issues. I am not a lawyer, but my understanding is that if someone testifies and clears up a matter from a previous testimony that is not perjury. They just don't like Phillips so it has always been a fantasy that he should have been charged.
The other thing is there has to be intent. That is the person has to know that they are giving false information. I think that would have been hard to prove in the case of Phillips. Others may disagree.