[macspoofing]

>He was on a flight that had a layover in Moscow airport, but the US revoked his passport, so he got stranded there until Russia eventually granted him asylum.

Not quite. As another poster stated, Snowden had his passport revoked a day before he cleared security in Hong Kong and boarded the plane to Moscow. The decision to allow him to board the plane could only have come from the top of Russian leadership. US also issued a request to detain him and again, the decision by Hong Kong and Chinese authorities to ignore this request could only have come from high up in the respective leadership chain.

His entire time Hong Kong is mired in controversy and implicates him as a defector (either planned or spur of the moment) - for example his visit to Russian consulate (with Putin himself acknowledging that Snowden met with Russian diplomats). Wikipedia has a good write-up [1].

[1]https://en.wikipedia.org/wiki/Edward_Snowden#Hong_Kong