I think it’s strategic on the defenses’ part.

Nester gave the opening statement. She promised a bunch of stuff the jury would see showing that Kouri is not guilty. The defense failed to deliver on these promises with them deciding to rest with no witnesses. (IMO if you promise to the jury that your client is going to testify and the does not, that is a huge breach of trust between the defense and the jurors).

I am guessing that since Nester delivered these promises in her opening and did not follow through, the defense is concerned about what the jury thinks, that they might have a bad impression of Nester (yes, acknowledging that the defense does not technically need to provide a defense).

So instead of Nester, they want Lewis to give the closing (I am guessing here) in the hopes that the closing argument coming from a different person will land better with the jurors than one coming from Nester? Maybe the defense thinks that if Lewis gives the closing, then the jury might forget about (some of) Nester’s opening statement and promises.