Only in an evolution debate would a simple statement of fact cause an argument.
We do double-blind studies because researches know that, no matter how nobel their intentions, KNOWING what result they want, and having access to data that could allow them to manipulate the results, the results often end up manipulated even though they would swear they didn't do so.
Like I said, it's standard practice, because it's a well-known phenomena. Several of the major "gaffes" that in evolutionary thinking were caused not by people TRYING to deceive, but people who were honorable scientists who simply saw what they expected to see.
Not sure how we would go about doing a double blind study with fossils but if you say so...
I realize that wasn't your point, but it does illustrate the different validation demands inherent in the various fields of science. While there is a possibility of a single scientist finding what he wants to find rather than interpreting the data accurately, the fossils are there for all scientists to see. Unless you are positing a huge conspiracy the chance that an incorrect or horribly biased interpretation will survive the scrutiny of many scientists, some who are at loggerheads with each other, is pretty thin.