I did the AI class and that was not the case. Stanford students were clearly separated from the online students. We didn't get the same assignments neither.
I took CS221 last quarter. So I can say that you got the same assignments and exams; you just weren't required to do the programming assignments. While ml-class was perhaps the third iteration of putting the machine learning class online, ai-class was probably the first time someone tried to put CS221 online; the professors simply felt that they wouldn't be able to automate the assignments in the time that they had. In fact, many of the YouTube lectures, which many Stanford students seemed to prefer, were often not available to us in time for the assignments and exams.