To be fair most, all? cases I have seen the Agency fills out the DS 160 but the applicant submits it, seemingly and who really knows this did not happen in this case.
The argument then being well I did not fill in the application, when it is pointed out they signed it, they go back to well I did not fill it out. All very weird.
Anyway turning up at an interview with a DS 160 filed which says you signed and being interviewed bases on that submitted and signed DS160 makes any further discussion moot. You owned it.