To be clear my interpretation of this transcript:

1. The defence attempt to call Dr Hall was during the prosecutions case, so it would compete directly with the prosecution testimony at roughly the same time.

2. The defence still could have called him, just 8 months later. (Reminds me of: “A lie gets halfway around the world before the truth has got its trousers on”)

3. This motion doesn’t appear to be in any of the transcripts I have which narrows it down to a pretrial hearing. This is also the only mention I’ve seen of this.