I believe he was talking about the "intro to C on Windows" video that was posted on Youtube.

Admittedly, it's an hour long so I don't have the time to watch it. Skimming over it though, it looks like he may be writing C code, but compiling it via Microsofts C++ compiler. That's just my guess though. The code he's writing has some Cisms in it (And no C++isms, though it's basically just a 'Hello World'), but it's in a 'cpp' file and I presume VS is using a C++ compiler to do so.