The Guardian gives a fair summary of the book's treatment of the allegations by a graduate student against Peter Ludlow at Northwestern. (It is less good on the allegations of the undergraduate; the most serious of her allegations were thoroughly undermined during the depositions in connection with her lawsuit against Ludlow and the university--Kipnis's book gives a better account of this.) An excerpt ("Hartley" is the pseudonym for the graduate student complainant):
[Hartley] and Ludlow had seemingly been in a relationship: a consensual relationship documented in dozens of fond texts and emails that Kipnis has seen. She was a 25-year-old graduate student, and he was not her supervisor. It wasn’t, moreover, until two years after this relationship ended that she rang her thesis adviser and told her that Ludlow had once had sex with her without her consent (it was this adviser who contacted the university’s Title IX officer).
(In fact, Hartley only reported the allegedly nonconsensual sex upon learning of the lawsuit by the undergraduate; and her faculty adviser then had a legal obligation to report this to the university's Title IX officer. As I understand it, the university had to pressure Hartley into making a formal complaint. That Hartley would have been mistaken about the date of the alleged incident two years after the fact is also hardly surprising.)
Kipnis says in the interview, that is part of The Guardian article, that she isn't trying to "defend" Ludlow, but her account clearly reads as an exoneration of him. (E.g.) Kipnis's account at times conflicts with things I know from other sources (see my parenthetical, above, as an example), but overall I found her persuasive. Ludlow, whom I know only slightly, comes across even in Kipnis's account as being at times a bit juvenile and unprofessional ("foolish" says Kipnis), but not as having done anything that would be grounds for termination.