Trying to Make Sense of What Happened to My Uncle's Body After His Passing

As-salamu alaykum everyone. My uncle passed away about two years ago now, and there's this one thing that keeps coming back to my mind that I haven't really talked about with anyone. He had been struggling with drug use for a long time-things like cocaine and injections-and honestly, his life was pretty rough. He was involved in a lot of wrongdoings like lying and stealing. In his final years, his health really declined, and the doctors said he had thrombosis, which ended up causing his death. When he passed, we followed the proper Islamic procedures and took him for ghusl before the janazah. After the washing, the imam shared something with us that completely shocked me and has stuck with me ever since. He mentioned that my uncle's body had turned a purple hue, the whites of his eyes were really dark, almost black, and there was this ongoing discharge coming from his body. I've never heard of anything like this before, and I'm honestly confused about what it could mean. I'm wondering if this is something that can naturally happen to a body after death, especially given his health issues and past, or if there might be an Islamic perspective or explanation behind it. I'm not asking to pass judgment on him at all-I just genuinely want to understand what might have occurred. If anyone has medical knowledge or an Islamic insight on this, I'd really appreciate hearing your thoughts. Jazakum Allahu khayran.