There's like a whole lot of possibilities with this one, like hogae could be just dead or maybe doha changed the body so as not to show dex or anyone that hogae is still alive somehow and maybeee hogae could've added an extra line in his mail to doha about dex's real identity or Anna can find out about it, orrrrr Since doha and seol already heard his voice (I think they did), they do know exactly who the criminal is, and they are just playing along with some secret plans of hogae OR Maybe I'm delusional and trying to cope up with hogae's death after Dojin's death since I loved both of their characters dearly
OR
Maybe I'm delusional and trying to cope up with hogae's death after Dojin's death since I loved both of their characters dearly