The deposition is not a time for you to present your malpractice case. Rather, it is a chance for opposing attorneys to ask you whatever they wish to know, to fill in some blanks, and finish preparing. It also gives attorneys a chance to evaluate your testifying style and determine how they will approach you at trial.
Therefore, simply answer the questions that you have been asked. Although the situation can and should be cordial, do not get involved in a lot of general conversation with opposing attorneys. They can be your friends some other time, but right now they are the opposition, and the approach and demeanor you present is important. Every attorney approaches depositions differently, so go into these sessions feeling flexible and comfortable. Also be prepared to move easily from one subject to another.