I'm not explaining clearly. Please let me try to explain better.

The defendants in the case told you that they don't have the contact information for the witness. The incident happened under a camera but Defendants destroyed the video. Defendants then released a document they intended to use at trial in their pretrial disclosures with the witness's contact information on it. This is weeks before the trial.

So the judge calls the witness on the phone and gives you and Defendants' counsel a couple minutes each to ask him questions, and it is obvious that his testimony is relevant.

Another witness was scheduled to appear at trial, and you spoke to that witness over the phone, but never took his deposition. The judge suddenly refused to let him appear and testify.

So in both of these cases you need the deposition in order to tell the appellate court what the testimony would be, so that they can decide if the testimony would have changed the outcome of the trial.