Report export requires additional permission on report form
A user without the permission "Edit reports" is not able to export reports as CSV/PDF from the report form at civicrm/report/instance/{report_id} using the action dropdown field, although those actions are contained within the field. The form is just submitting and no export happens.
However, using the link (civicrm/report/instance/{report_id}?output={csv|pdf}), e.g. on the report list on civicrm/report/list, this is possible as expected.