I am not even sure that in most cases it is even making excuses for Jeremy - it is more looking at the evidence available and the interpretations. A lot of the character assassination is counteracted by for example Jean the family housekeeper who never saw any family arguments . Is that an excuse ? Or just looking at peoples statements and motives for their evidence?
Is it an excuse to say a phone call could have happened ( until proven otherwise) ?
Is it an excuse to point out there was no forensics linking him to the crime?
I could go on.
I made excuses in respect to the phone call - I argued that it could have happened when I had REAL doubts about it.
There is a MASS of circumstantial evidence (even if you don't believe the silencer) and it's an excuse to deny it exists because he was convicted on it.