From Lakewood Guy:
If you were walking down the street and you met Rashi and you asked him the time and being that his watch had stopped he told you the wrong time, would that bother you? Would you be required to accept that the time is now an hour earlier?
Now, for the slow, let me rephrase the question. If you were thumbing through the chumash and you encountered a Rashi that was factually incorrect oweing to the fact that Rashi relied on bad science, would you be required to pay obeisance to it?
[The Lakewood Guy blog]