The big debate before the big debate was about whether moderator Lester Holt ought to fact-check Donald Trump and Hillary Clinton on the spot or simply ask questions and keep time. Once the proceedings got underway, the NBC News anchor's first major decision point arrived when Trump challenged Holt on a basic statement.

This was the exchange:

HOLT: "Stop and frisk" was ruled unconstitutional in New York because it largely singled out black and Hispanic young men.

TRUMP: No, you're wrong. It went before a judge who was a very against-police judge. It was taken away from her, and our mayor — our new mayor — refused to go forward with the case. They would have won on appeal. If you look at it, throughout the country, there are many places where it's —

HOLT: The argument is that it's a form of racial profiling.

TRUMP: No, the argument is that we have to take the guns away from these people that have them and that are bad people that shouldn't have 'em.

Moderator Lester Holt asked Donald Trump about his support for "stop and frisk" policing during the first presidential debate at Hofstra University Monday. (Photo by Brendan Smialowski/AFP/Getty Images)

For the record, "stop and frisk" was ruled unconstitutional for the exact reason Holt identified. But Holt chose not to engage Trump in a true-or-false argument. (Later, Holt directly contradicted Trump's false claim that he opposed the invasion of Iraq — something Holt's NBC colleague, Matt Lauer, was widely criticized for not doing at a candidates forum.) Instead, Holt pivoted to the underlying issue. Whatever happened in court, the question about "stop and frisk" is whether it is a kind of discrimination or an effective police tactic. That is what Holt wanted Trump to address.

Tuesday-morning moderators will surely argue about whether Holt did the right thing by declining to push back hard on the facts. But if his goal was to keep the conversation moving and not entangle himself, he achieved it.