This does depend on how bad the RAM was. The RAM on this machine was so bad that the fs was not the only thing misbehaving by any means.
Rare bitflips are normally going to be harmless or fixed up by e2fsck, one would hope. There may be places where a single bitflip, written back, toasts the fs, but I'd hope not. (The various fs fuzzing tools would probably have helped comb those out.)