Yes, science does matter when it is practiced properly. All of the medical organizations listed in the above video approved of glyphosate, the active ingredient in the weedkiller RoundUp, until the beginning of 2014 when the International Journal of Environmental Research and Public Health published a study showing that glyphosate causes chronic kidney disease.
This study was then confirmed by the International Agency for the Research of Cancer in 2015 that showed that glyphosate causes non-Hodgkins lymphoma. So far, fourteen countries have banned glyphosate. For the makers of RoundUp, science matters only if it was before 2014.