The pilots have, according to the prelim NTSB report, denied they saw aircraft on the taxiway, in fact, they denied being on the taxiway.
That's not exactly what the investigative report says:
In postincident interviews, both incident pilots stated that, during their first approach, they believed the lighted runway on their left was 28L and that they were lined up for 28R. They also stated that they did not recall seeing aircraft on taxiway C but that something did not look right to them.
What's missing is the context behind these statements. When during the first approach? On short final? Just prior to the go around? Even after the go around?
E.g.,
NTSB: "So now you're 4nm out, visual, making the first approach. Did you see the other aircraft lining up for take off?"
Pilot A: "No, we didn't see them, although something didn't look right on what we thought was the runway"
Pilot B: "Yeah, that's when we saw some lights, so we called tower, but he told us there's no one on 28R but us"
NTSB Update: "In postincident interviews, both incident pilots stated that, during their first approach... they did not recall seeing aircraft on taxiway C but that something did not look right to them."