It's in the LICENSE file. With a MIT license, you assign a copyright to the project, or to a certain set of files. The Spegel license attributes copyright to "the Spegel authors", while Peerd attributes it to "Microsoft Corporation".

If some of the peerd code was lifted from Spegel, it's blatant stealing. Code attribution is the only thing a MIT license asks people to honor, and Microsoft couldn't even do that.

MIT license doesn't require copyright headers. You need to credit the authors even if the files don't have headers.