As faculty at UNC CS, I can mournfully confirm this is indeed the case. He passed peacefully at his home in Chapel Hill earlier this evening, surrounded by family.

Dang can you clarify why you found "Columbia CS" credentials more credible than "UNC CS"? I'd like to say that's a pretty shocking position but sadly it isn't.

I didn't find that, nor say it, nor imply it, nor did such a possibility ever enter my consciousness until now. I'm mystified that such an interpretation could even arise! Do you want to explain how it occurred to you?