Expert Witness Testimony

The job of the Forensic Scientist is to gather the scientific and industry data that makes up the body of knowledge used by the standards setters to present a consensus guideline. A flooring expert must know the relevant information published by the wood flooring industry, the ceramic tile industry, the natural stone industry, carpet manufacturers, flooring chemical companies, and floor testing services.
 
This work is exacting because the courts want a window into the truth. I have testified in many trials, and been deposed a great many times. My goal is to present an unbiased roadmap to how floors work. I get really miffed when an expert makes up statements that lack documented corroboration other then their own self-serving view as a fact.
 
I have been involved with an opposing expert whose focus is on one side of the isle. He makes statements as facts, but changes the result of those facts. In one deposition he states that if you burnish a floor coating it will make the floor sticky, in another deposition he states that if you burnish a floor coating it will make the floor slippery. He has stated that if you tap a piece of stone with a piece of metal it will sound the same as tapping that stone with a piece of rubber.
 
Are these the opinions of an expert? Evidence must be more that “I think it’s so”. Please forgive me for venting