They did not steal it, but you have to give Xerox credit. Xerox was way ahead of the game, light years, but their management in all their infinite wisdom did not believe the idea of a paperless office, and so let the Star hit the dump heap. Jobs saw it and knew it was the future. LISA was created and we were on our way to what everyone now takes for granted. HP made a similar error when they allowed Jobs and Wozniak to have ownership on the prototype Apple that they developed on HP’s time. They did not think anyone would want or need a pc. I sold computers from 1980 till about 1985, needed to pay for college! Remember the portable Compaq, the HP touch screen, the IBM AT? The good old days when DOS was king! ;)
Ironic, in that many years earlier, the inventor of xerography pitched his idea to GE, and GE thought "mimeograph is good enough".