Reaching out to the Youtuber to get the stuff before getting police involved is most likely better for everyone concerned. It reduces the risk of violence, it speeds the process, it minimizes the chances of the dude getting a criminal record or having to spend time and money going to court because the an officer recommends and prosecutor decides to press criminal charges (which is in their hands once you go them with a report of possible criminal activity, which is all they'd be interested in)...
But, if the cards were stolen, it virtually guarantees that the physical evidence completely disappears.