Chemical weapons in Syria

So, Syria bombed ISIS in Syria and apparently damaged a rebel chemical weapons storage site releasing poison gas which killed at least 70 people.

But the lapdog press in the US is claiming that Syria launched a chemical attack and has condemned Russia and Iran for supporting them.

Syria is winning the war. They have ISIS and the "rebels" largely defeated. Why would they use chemical weapons now?

The terrifying thing is that ISIS has chemical weapons and it doesn't seem to bother anyone.