The federal government denied a 68-year-old Chinese citizen permanent residency last year after arguing he had trained Chinese spies — and might be one himself. But a recent Federal Court ruling says the information the Canada Border Services Agency (CBSA) used in its assessment of Liping Geng's past was "dubious" and "overreaching," raising questions about the credibility of CBSA's intelligence wing. A Federal Court judge has now quashed the CBSA's decision in the case of Liping Geng and has ordered another immigration officer to review his case. Geng taught English at a school in China that — as Federal Court…