> Isn't he residing in Russia now?

The only country that has demonstrated the ability to resist pressure to extradite people wanted by the US? Yes.

> ...could his knowledge of our systems and processes somehow have helped Russians do the hacking prior to 2016 US elections?

bwahaha, so now he is involved in muh Russian collusion? The answer is yes, which is what makes your insinuation really funny - they did all the things he would have advised them not to do. So you could interpret that as evidence that he didn't provide them that information, and is therefore not a Russian spy.