An unpublished report by the OPCW Fact-Finding Mission confirms that the April 2018 chemical incident in Douma was a false-flag operation perpetrated by the rebels.
The "unpublished report" appears to be an engineering assessment carried out by one individual who, contrary to Sputnik's false claim, was never a member of the Fact-Finding Mission and is not currently employed by the organization.
The individual, however, was affiliated with the OPCW as an engineer and apparently had access to materials gathered in the course of the Douma Fact-Finding Mission, and based his/her conclusions on the same evidence pool. An OPCW press statement confirms that "all information was taken into account, deliberated, and weighed when formulating the final report regarding the incident in Douma." The OPCW Technical Secretariat is conducting an internal investigation about the unauthorised release of the document in question.
Regardless of the leaked document's authenticity, its conclusion that the cylinders could not have been dropped from helicopters:
See the original debunk here.