You can't just ignore the photos, videos, testimonies, articles in international media with different ideologies only to base your thesis in "It's my opinion". Well, in fact you can, but your opinion doesn't deserve to be respected.
Nobody questions the attack - the only unknown is who perpetrated it. Whoever planned it knew very well that using a chemical weapon, especially on civilians, is likely to meet a very strong reaction. We've seen it in the past. That raises questions why anyone would do it, especially Assad who is now winning the war.
There are so many possibilities here. One of them is that Trump is being manipulated by the intelligence.