Right now, the OPCW workers are there to try and sort this out.
"Some others" can always mean, the Russians, the Regime, the Iranians, those like Alex Jones, etc. say that. Even a few politicians like Rand Paul and that State Senator Black in Virgiina.
Maybe the OPCW can sort it out. Again, indications are it was dropped from the air, generally, not in the capabilities of the Rebels, Jihadists, etc.