If that was the case, is it possible for a deer to travel 700+ yards after a 1 lung hit???
Sure can especially if pushed. Some believe (including myself) that it can survive a one-lung hit. But IMO, you did the right thing by getting on it. About your only chance of recovery with a single lung (nothing else hit) is to have the deer bleed out. I'd really search hard around the last point you had blood. It could have ran out, and beded nearby.