The Wikidata repo UI is not properly initializing on Items on Wikidata.org with debug=true.
This can easily be verified in at least Firefox by going to a random Item and appending debug=true to the URL.
I can't see anything obviously weird in these cases except for resource loader leaving some modules into the "loaded" state.
Example:
mw.loader.getState( 'wikibase.parsers.getStore' ); "loaded"
Not sure what to look at next…