If you have screenshots or videos, you can link them using an in-game ticket to show one of the GMs. Click on the "Help" button in the game (The red "?" mark), select "Stuck" and click the "Still stuck; page a GM" button; it'll let you create a ticket where you can describe what you witnessed and provide links to any screenshots and videos.
Alternatively, you can also send any of the
GMs a private message here on the forums with the same information and links.