Earlier quoted context omitted.
What they meant is wrong. I can consult Merriam Webster, which agrees with what I said. https://www.merriam-webster.com/dictionary/circumstantial%20... Or Britannica https://www.britannica.com/topic/circumstantial-evidence Or Cornell https://www.law.cornell.edu/wex/circumstantial_evidence Or basically any single law firm or courthouse https://www.shouselaw.com/ca/defense/legal-defenses/circumst... https://www.ojp.gov…
https://www.merriam-webster.com/dictionary/circumstantial 1. belonging to, consisting in, or dependent on circumstances 2. pertinent but not essential : incidental The original comment used the word correctly. Because dictionaries describe how people actually speak, not prescribe rules on how to use words. That's why they get updated every so often as word usages change.
In other words, the appropriate definition of a term of art is... circumstantial. ;)