A few quick points: First, yes, they can identify chemical agents by satellite. In this case, I heard, they identified the agent from the bomb crater. Each munition leaves tell-tale evidence of its composition. Also, the pattern of dispersal will indicate whether it was inadvertent or deliberate.

With regard to notification, that is required for non-hostile parties. My understanding is that Russia was notified 30 mins before the strike - long enough to get personnel out, but not equipment. It's likely local Syrians were alerted by them, but not anti-aircraft units. Since the primary targets were fixed facilities, those couldn't be moved anyway.

It would be interesting to know how pissed the Russians are about the chemical weapons. Are they complicit, of ineffective?

A well reasoned argument is like a diamond: impervious to corruption and crystal clear - and infinitely rarer.

Here, as elsewhere, people are outraged at what feels like a rigged game -- an economy that won't respond, a democracy that won't listen, and a financial sector that holds all the cards. - Robert Reich