I've been watching lots of Jodi Arias. Juan is doing everything for a reason. He's got to lay the foundation for his rebuttal case.
What you want to do is lock a witness into a story - not easy with Jodi. He has to get a witness to deny something or commit to a position. Then, on his rebuttal case, he can call witnesses to rebut that testimony. If a witness denies something and has admitted it to someone earlier, you can bring in a witness to impeach their testimony, someone who say, yes, she admitted x to me before. You can't call someone to rebut or impeach if what you're rebutting or impeaching isn't in evidence. That's what I think he's doing. You also have to consider everything you do in a trial is leading to your closing statement. He's doing fine. This is the part of the case that will be the least favorable to him, but he's doing pretty well.