Edit: I suspect the professor mentioned there is Mike Shamos and the transcript misspelled his name. http://euro.ecom.cmu.edu/shamos.html
> And then Stallman freaks and he gets a copy of my source code, does a whole lot of editing. He doesn't actually-- You know, he edits, like, almost all of the copyright headers, but he doesn't edit all of them and he only kind of thinly edits it and then he re-releases it as GNU Emacs. And then IBM and Digital Equipment pick that up and start distributing it. So these, so the two guys in the garage who had been doing okay suddenly find that IBM and DEC are distributing their thing for free and they're dying. So they decided to sue DEC and IBM and they got a, you know, and that turned into a big, big court case. They won. It was kind of a pyrrhic victory. You know, so IBM and DEC paid them some damages, but that didn't stop GNU Emacs. .. ..he hadn't actually changed all of the copyright notices. So it was like, duh. But then it sort of took on its own life and it's become the GNU Emacs that everybody uses.
I find it hard to believe that RMS was simply removing copyright from other listings. In his description found in [0], he was replacing a lot of it while using the display portion. Presumably that's all replaced after the lawsuit.
The history of EMACS and TECO predate Gosmacs, this all seems rather silly.
"EMACS is available for distribution to sites running the DEC Twenex operating system. It is distributed on a basis of communal sharing, which means that all improvements must be given back to me to be incorporated and distributed." [1]
[0] https://www.gnu.org/gnu/rms-lisp.en.html
[1] http://dspace.mit.edu/bitstream/handle/1721.1/5736/AIM-519A....