text: good point, i did not notice the age of that changeset :-)
  https://www.openstreetmap.org/note/754413
  which you resolved is nearby and may also refer to a garage as building, so if someone does a survey or the aerial imagery is updated, whoever acts to resolve this note should have a look nearby to see what else may not match the map data.
  i noted when comparing backgrounds somewhere else you commented (Glarus?) that the map data based on bing was missing some recent buildings from newer but unaligned imagery, hardly uncommon in der Schweiz.