The crash killed 40 passengers, injured 191 and shook the nation’s confidence in its ambitious high-speed rail system. Mr. Cao, 33, a Chinese-American importer from Colorado, barely survived; he lost a kidney and his spleen, and head injuries have left him mired in a perpetual daze, unable to stay awake for more than an hour or two. His parents, naturalized American citizens taking him on a triumphant tour of their native land, were killed. As Mr. Cao has struggled to recover over the past year, he has found himself drained by a different sort of battle: trying to wrest compensation from the Ministry of Railways, an unbending government behemoth unaccustomed to dealing with determined foreign citizens.