I just walked out of my room and BAM, pungent odor of weed in the hallway. I called the front desk and they sent up a guy who paced up and down the hall, but could not identify the culprit.

Assuming it's not an "inside job" (i.e., weed smoker knows hotel staff and the security check was just for show) -- I'm surprised the hotel didn't make more of an effort to identify the person. Seems like easy revenue to me: hefty smoking fine (non-smoking hotel) and forced early checkout (so an upgraded room is ready for an early check-in the next morning).

IMO, identification would not be difficult, as I'm on the club floor. First identify all non-SPG/non-elite guests on this floor (presumably elites would know better) and start knocking on rooms....