Did this interview answer f up my chances?

I just did a second round in-person interview for an IB SA role. Everything seemed to be going pretty good, but right in the middle of a conversation about my interests outside of work/school, one of the interviewers hit me with a technical out of nowhere. The question something like "Where do you use tax rates in your DCF model?" My response was that you use it in two places: when calculating unlevered FCF (EBIT*(1-T)) and when doing the cost of debt portion of the WACC calculation (Rd(1-T)). He then pressed me on if it would also be used for calculating cost of equity. I said not with the CAPM, and then he asked about beta in particular. As I was thinking strictly of nominal beta calculated only with variances and covariance (rather than unlevered beta where you do incorporate 1-T), I said no again. Did this seemingly minor screw-up kill my chances?