Love this thread - very useful as I am having this exact issue (in user testing, people are closing the entire browser window) - did every thing told to do here, but it didn't go back to the home page.
The final slide opened the web object, and I could see the code in the web object was correct, but it just stayed on the final slide and did not close the SCORM or go back to home page.
Could it be something in my Articulate or moodle settings?
I kinda need to fix this ASAP so i will be looking forward to your replies! Thanks!