So it was a subsequent hotel guest found the vial, probably thought it was coke (or some drug) and took it to the front desk (for the hotel to call the cops maybe). So this quest, along w/the front desk worker were in contact with the vial (before anyone knew what it was). And the housekeeping staff would have changed sheets, vacuumed, picked up towels, etc that could have been exposed them to the powder as well. So the original occupant (theorizing here) who left the vial behind is long gone.
Yikes.