Legal Question in Administrative Law in California

Yes. The relevant provision of law is Government Code section 11511.5, dealing with prehearing conferences. Subsection 11511.5(b)(5) lists "objections to proffers of evidence" as one of the possible topics at a prehearing conference. You should probably read the entire section, as it deals with essential procedural matters. Also please note Gov't. Code section 11513, in particular subpart (c), "The hearing need not be conducted according to technical rules relating to evidence and witnesses....." etc. Finally, I think if the subject matter or possible outcome of the hearing will have a major bearing on your career, you need to be represented by an experienced (in this area of the law) attorney.