If YOU had a higher IQ, you might have noticed three salient points about this "pinning down" of Jordan Peterson:
1. The questioner intentionally obfuscated his first example by referring to "making a cake for a gay wedding." This was an obvious reference to the SCOTUS decision which upheld the right to refuse personal services (decorating a gay cake and serving a gay wedding) based on religious grounds. Peterson agreed with this decision.
2. The questioner then provided an example of "making a cake for a black couple." As he should have known, simply selling cakes to customers is not a personal service, but part of public commerce. As such, it is unlawful to discriminate on the basis of race. Peterson agreed with this.
3. The questioner then surreptitiously conflated these two examples in the guise of a simple civil rights comparison. Peterson then agreed that, on that basis, neither black nor gay people should be refused commercial access. Far from being "pinned down" by the questioner, Peterson's agreement within this context was an example of high IQ open thinking.