I took the comment to mean that, they, the authorities, are correlating the presence of MJ without the a control group.  For example if everybody in Colorado partook in Weed ( THC)  then 100 percent of the accidents would have (THC) involved , and nothing could be learned no control statistics of accidents from non users.   Since everybody has oxygen (air) in their system then we might as well conclude that Air is causing accidents , by this shoddy misuse of a statistic. Media and journalist often use these correlations to make a point.  And from this article I can't figure out if the stat is meaningful.  For example,  I recall reading a statement many years ago that only 10 percent of the worlds CEO's are obese , and therefore if you are obese you are unlikely to be a CEO, but without siting the how many people in the General population are obese the statistic is meaningless.