Should I feel bad to HR about what happened?

I casually contacted HR at a firm earlier this year. After some back and forth, I decided to personally recontact this one HR person after a few months about an open position. I forwarded my resume and the people on the hiring team seemed to want to interview me. I completely bombed the interview. It turned very detailed and I started getting questions about technical skills that I haven't used in over 4 years. I have them listed on my resume because I really was competent with them at the time, but I do need a refresher. Once I get back in the swing of things, I am able to pick it back up quickly.
I mean, I may have stretched the truth a little, but nothing too far fetched that I can't relearn quickly. At first, I was trying to BS some of the answers but I ended up just saying that I didn't know. I thought the interview was going to be focused much more on what's happening in the market and not get a bunch of programming questions. When it comes to basic programming, I usually have the code that I'm working with in front of me at work and I am able to solve them easily (along with having resources to find answers if I'm stuck on something). On the phone, it's a bit different.

I was expecting the interview as a 1st round to be more about let's talk markets and what you did in your previous jobs, but it turned into mathematical probability + in-depth technicals + brainteasers + programming/SQL questions.

I'm kicking myself because the brainteasers were easy after looking back on them while not being under the pressure in a phone interview. I bombed the interview and it was one of my worst performances that I'm embarrassed about. I feel bad for HR because of what happened. It feels like a network who helped you and you bomb it. Has something like this happen to you before?
Do you think this HR person who helped connect me will face any backlash which may come back to me?