Why did the speaker say Peter was not the first pope?
Peter was not the first pope because he never had a ministry among Gentiles. His ministry was to Israel, as seen when he addressed the rulers, elders, and Israel, not Romans or Gentiles, and the gathering was all Jews. So the speaker rejected the claim that Peter was the first pope on that basis.
Les explains that Peter is always the spokesman, even since his earthly ministry, and was filled with the Holy Spirit at this point. But Les does not agree Peter was the first pope because Peter never had a ministry among Gentiles. In the passage, Peter speaks to the rulers, elders, and Israel—all Jews, next of kin of the high priest—not to Romans or Gentiles.