Anything along the lines of “Ah! Thanks for pointing that out. Yes, x is indeed y, which means xxx”
If you've noticed the mistake or understand their correction, all they need from you is a clear awareness of that, a visible course correction, and a smooth/confident transition.
Simple as that!
Always remember what they're looking for:
"Someone who can approach a complicated problem and think + communicate in a structured way in the right context+objective of the case, while being personable, adaptable, and coachable, so that, ultimately, the interviewer can see themselves working with this individual and putting them in front of a client."