Yea, this is a very bizarre framing. I understand that researchers hypothesize that a Marijuana-driven causal link is possible, but theres a well-established, strong causal effect in the other direction that first needs to be controlled for. In that light, the statistic is framed very dishonestly in the article.

(Though perhaps dishonesty isn't the correct word to use here: I don't have a high prior on the journalist even understanding this complaint)