ok - I presume this statement " in the course itself, it reports a passing score and a "complete" status" - you mean totaras activity completion? - if you're using the grade option Totara's activity completion ignores the lesson_status completely.

My guess is that the user either

A: re-entered the SCORM and exited without completing which set cmi.core.exit to suspend and updated the lesson_status.

B:- they closed the SCORM package before it updated lesson_status to completed.

To fix "A" above you could use the force new attempt option which will create a new attempt rather than re-opening the existing "completed" attempt when the learner returns and enters the SCORM after previously getting a completed/passed attempt.

To fix "B" you may need to make some changes to your SCORM package - you may need to ask for help in the articulate forums for this.

hope that helps.