Yeah, great film, holds up well over the years. But no Harvard law student would have thrown his unopened grades into the ocean. Particularly one that was as dedicated and competitive as Hart. It would be like a lawyer trying a case and leaving the courtroom before hearing the verdict. One can understand and, in a mercenary way, perhaps admire Hart if he pretended not to care about the grades for the sake of impressing his erratic, anti-establishment/anti-hippy girlfriend. She doesn't make much sense, but she is cute and alluring. But to actually throw the grades into the sea? No.
Apart from that, the scenes of the workings of law school are pretty terrific. The characters of the study group are, for good and bad, very similar to people you actually find at law school. Particularly Bell. (By the way, did anyone notice that Hart's 3rd year advisor was Thirtysomething's Miles Drentell? He is exactly the type that would say, "Grades matter.") Yet, like lawyers themselves, they're not on the whole really awful people. Ford, the quintessential Harvard prepster, bails out James Naughton's character in class and even goes so far as to say that the subject is very difficult to understand. Hart himself is obviously very decent. And Kingsfield is meant to be feared, but moreover respected and admired.
So the romance is a bit unrealistic, but nothing approaching Ally McBeal silliness. That aside, it's a solid film worth seeing more than once.