The docetns are at British The Guardian and German Der Spiegel and the person extracting those initially sits in Russia and who knows who got copies or extracted them.
The deputy chairman claimed. Not the committee conceded. Whoever wrote conceded missed or wished to obscure the deputy chairman could have lied. Failing to get anything from Snowden would have embarrassed Russian security services. Or it could have been an assumption if the English translation is accurate.[1]
At least this claim could be probed. Most claims in the report relied on proven liars.
https://intelligence.house.gov/uploadedfiles/hpsci_snowden_r...