Galan was almost killed in Medellin and after the assassination attempt was thrwarted, the mayor of Medellin and the police commander of police in Antioquia were both killed. They had been with him and it was also done as retaliation for disrupting cartel business on home soil. They killed Rodrigo Lara, who was like the Colombian equivalent of the U.S. attorney general.

The cartel as an organization I guess technically is responsible for Galan's death but Pablo commanded the cartel. It was somewhat of an oligarchy (El Mexicano, the Ochoa brothers, Lehder, et al) but Pablo was el capo de los capos.