They did not warn that the lab was dangerous or in any way poorly run. That's the spin that Josh Rogin has repeatedly tried to put on the diplomatic cables. The actual cables (written by diplomats, not experts) merely stated that a lab which had not yet opened did not yet have enough trained staff to operate at full capacity. The cables said that in order to ask the US government to continue its training program for staff at the lab. The cables actually complain that the Chinese government's safety regulations are too strict - not allowing the lab to work with Ebola.