I think Trial log should be doable (starting and ending it) with standard dialog in addition to the voice command. It more simple especially to the people who never used the system, and would make sense that all NPCs would be fully intractable through standard dialog. The voice command should definitely stay, but I think this could be a more user friendly approach.
Secondly a bit more complicated suggestion:
About the naming of the log item: What about if the scribe would ask after log has begun to state the name of the accused, the judge and what is one accused of for the record? When recording is stopped, he would ask the Verdict and Sentence, before making the scroll.
The scroll could have be done the following way: <name of accused> <IG date>
Description would have following lines: Judge: Accused: Crime Accused of: Verdict: Sentence:
This would make the record items more useful for IG reference.