The interpretation of human behavioiur is best done by peers. Not by the investigator.
Peers are people of the same profession as the person involved. You may consider leaving this assessment, or interpretation, to a specially appointed committee. When you are the lead investigator of the event, try to withold judgment in any form whatsoever and leave this to the Just Culture Committee referred to elsewhere. Nonetheless, it is certainly useful to make sure you have all the relevant factors needed for the assessment of human behaviour: what happened, where, how, and, most importantly, WHY. Try to describe the intent of the behaviour accurately and truthfully.