The crew pattern of Dragonair has been pretty poorly-planned, I'd say and I guess this is the main problem.
IIRC, they have Shanghai+ HGH+BLR pattern (or something like that, some ports in Mainland China), and these Mainland ports always have severe delays, so probably the crew had either exceeded their maximum working hour by law or they had not enough time to perform turnaround. The departure time may be actually later pushed back due to the fact that they cant find another set of crew for substitution, as KA is short of crew.