You are right, unwisely I commented before finishing it (it's a long document). I offer my excuses.
I found specially damaging for the Syrian version the point 24 and 26 in the annex II:
"The Syrian Arab Republic informed the Mechanism that the pilot had later been shot down and was missing in action. "
"During a briefing given by the Syrian Arab Republic to the Mechanism in Damascus, a representative of the Syrian Arab Air Force stated that no aircraft of the Air Force had attacked Khan Shaykhun on 4 April 2017. This contradicted the public statement made by the Government [..]"
I found specially damaging for the Syrian version the point 24 and 26 in the annex II: "The Syrian Arab Republic informed the Mechanism that the pilot had later been shot down and was missing in action. "
"During a briefing given by the Syrian Arab Republic to the Mechanism in Damascus, a representative of the Syrian Arab Air Force stated that no aircraft of the Air Force had attacked Khan Shaykhun on 4 April 2017. This contradicted the public statement made by the Government [..]"