You’re not completely crazy, the side of the Busan definately says Hanjin, but such things are commonplace when dealing with the Chi-coms. The ship that brought all the AK-47s into Oakland in 94 also had Hanjin painted on the side, and it was also COSCO owned.
Hmmmmm...may be time to look deeply into the South Korean HanJin Group to see if there are connections. Next project.
I found no connection perusing both COSCO and HanJin sites, however due my background in the Container Shipping Industry I am aware that it is not unusual for such organizations to lease/charter equipment such as these vessels amongst one another. The Busan which is apparently named for the Port City in S. Korea formerly known as Pusan may be leased/chartered to the COSCO Gp.
Just an educated guess.