They really only corrected Trump on a couple of things.
They pointed out that its not legal in any state to kill a baby after its born.
They pointed out that there was no evidence that Haitians were eating everyone's cats and dogs.
He said many, MANY other incorrect statements that were not live-Fact checked by the moderators to go along with those that Harris uttered. So its clear they were only live checking his most ridiculous, fantastical statements.
The one exchange that I thought was questionable was when Trump was claiming that Harris met with Putin but failed to stop him from invading Ukraine... which was apparently false, but the moderator then turned to Harris and asked had she ever met with Putin. That kinda felt like they were leading her because they obviously already knew the answer. So whether it was false or not it seem to me it would have been more appropriate to let Harris decide her own response rather than leading her with a question with an obvious answer.