Overexposure is overexposure. Negative film overexposes just as much as digital, however there are a few main reasons why it is more "forgiving" (i.e. more able to be salvaged).
Digital is a direct positive. When digital sensors are exposed by an amount of light that exceeds the minimum amount of light that the computer has been designed to label as maximum white, everything past that amount of light is labeled the same as the white itself, even though it was brighter in reality. (It being a direct positive, where is that extra light beyond the light that is placed at maximum white going to go?)
Unlike this, negatives are capable of capturing and storing tonal differentiation far in excess of the negative densities that would print as maximum white on a normal print.
A "normal print" is a print made at the printing parameters that result in a perfectly-exposed print (note that I did not say "perfect," but "perfectly-exposed") being made from a perfectly-exposed negative. The same times and f stops will theoretically work to make a perfectly-exposed print from any perfectly-exposed negative, and thus to accurately carry forward the negative densities to their respective "opposite" normal print densities. In other words, if you are calibrated to print a perfectly-exposed print from a perfectly-exposed negative, when you print an overexposed negative using these same print parameters, you will have a print that is lighter than normal (and vice versa).
Because of the fact that the negative, unlike digital, can hold information beyond that which is placed at maximum white, and the tones on the negative are reversed when the print is made, all those super bright parts of the composition (i.e. those exposed to negative densities that relate to print tones in excess of maximum white on a normal print) can be brought down into the print by making alterations from the normal printing parameters.
On digital, once the initial exposure is over, anything not falling within a relatively short range is assed out of being anything but maximum black or maximum white. The same happens with film, as far as tones being assed out if they land off the edges of the dynamic range, however, the range is much larger than the range of digital.