In episode 5 (Fail-save) of Legends of Tomorrow, Gideon mentions that no one has ever broken out of Koshmar. As in that part of history, no one would have.

But at that point of the chronological timeline John Diggle, Lyla Michaels and Floyd Lawton have escaped the prison.

Gideon is from the future and I feel like she would know that. Even if it was covered by the Russians. Oliver Queen helping his friend break out his (ex-) wife must have been part of his (Oliver's) biography.