> Isn't the solution to clarify that the student senate is not an official body of the college and that its views do not represent the college's views

I don't even think that's necessary. Sachs is leaving out a lot of the context/facts in this case... my understanding is that what made the university liable for the student senate's actions is that the university administration started endorsing the position taken by the senate in various ways, for example by suspending business with the bakery in response to the senate's resolution.