Low GMAT candidate with IB aspirations interviewing at Elite Schools

Hi guys, I recently interviewed at an Elite School for the Full Time 2 year program (think US News rank 8-15 schools) and I'm trying to figure out how the ADCOM is thinking about my application. To give some context, I scored a 640 on the GMAT (took it once, probably underperformed, but couldn't retake before January deadlines) and have an otherwise very solid application with a great story & essays, amazing recs from some big wig partners in my firm, several impressive extracurriculars/leadership, and a respectable 3.4 GPA from a top public university in the US. I was interviewed by an admissions committee member who told me that the interview was "blind", meaning that she hadn't reviewed my application, however, she had some notes from the ADCOM members who did and she wanted to address these points. The interview was relatively standard and conversational until we got to the part about addressing the comments from the ADCOM that reviewed my application. Since my story is centered around a transition into investment banking, she mentioned that many investment banks will not even look at a candidate with a GMAT below 700 and asked me how I plan to a) tackle the recruiting process when most banks will rip up my resume before even glancing at it through their GMAT screening and b) If I happen to land a conversation with a banker, how I will get around addressing my GMAT of 640. This question caught me a bit off guard because you would think that if they were so sure I was done for in the IB recruiting process, why invite me to interview in the first place? Anyways, I told her that I would be aggressive with my networking and make sure to score well in Finance and Accounting classes while in the program to prove my capabilities and also leverage my prior experience in M&A and financial modeling (not IB) to prove I can do the work. However, this was not enough of an answer for her and she pressed the matter further... ultimately, I caved in and said that I would retake the GMAT if I had to. She then moved on and we finished out the interview with other more standard culture and fit questions. In all honesty, I'm glad that the ADCOM digs deep into your story and really probes any holes in your application but it sure made for a relatively tough interview on my end . If you guys have any input on a similar scenario / experience I'd love to hear how you handled it and how it turned out! I was lucky to grab several programs' attention so I still have interviews at a couple programs with GMAT averages of 710-720. Any input on how to handle this in the future would be appreciated.

Question for the community:
1. I have this deep seeded feeling that I was on the "We'll most likely reject him, but let's interview him and see what he has to say, since he has an otherwise great application" category. Do you guys agree? I don't feel good about my chances based on that interview experience.

2. Do you think I should do anything post interview? i.e. reach out to my interviewer to somehow address this matter?

3. Was mentioning that I'd retake the GMAT a mistake? I feel like it may signal admitting defeat and that they are in fact correct that I'd done for in IB with this score (I wholeheartedly disagree)


Pro Tips for those that are on a similar boat: (I should have said these during my interview but they didn't come to mind on the spot)
-Mention that not all IBs use the 700 cutoff, mainly middle market banks, and you plan to networking heavily here as well (not just BBs)
-Mention that you will leverage the alumni network and the MM banks to land interviews

Thanks everyone!