Different questions need different support
Motive concerns a reason for an action. Opportunity concerns the circumstances that could allow it. Evidence of a dispute does not establish presence at the relevant time, and presence does not establish a reason. A character can have one without the other. Keeping them separate prevents an emotionally persuasive conflict from becoming a substitute for the sequence of events.
Worked example: an angry letter
A letter expresses anger about money, while a log records a visit to the relevant building. The two facts may matter, but you still need to connect the dispute to the event and identify what the visit record actually establishes. The letter might concern an older disagreement; the log might record an expected appointment rather than a completed arrival.
Reconnect through the case
In your Somatry notes, give motive and opportunity their own source references. Then test the connection between them against timing and identity evidence. Do not treat a character's unpleasant behavior as a motive merely because it makes them easy to dislike. A report should explain the reason supported by the fictional record and the circumstances of the action, with neither field borrowing certainty simply because the other sounds convincing.