The problem as I understand it is precisely that the spreading activation model doesn't include any natural way of doing that filtering.

Well, it may not be obvious how the error correction works, but it still explains the part that generate the hypotheses to be chosen.

This is similar to the stroop effect, and from studying that kind of stuff, they've figured out which part of the brain (ACC) actually does the error correction. Since it's a completely separate part of the brain that handles error correction, there's no reason to think that the part that generates the errors works differently.