The following auction occurred:
After passing 2♥, East removed his cards from the bidding tray as North did too. So when North passed the tray through to South and West, they thought that 2♦ had been passed out and removed their bidding cards from the tray.
West led and North put his hand down as dummy. When told to put the diamonds on the right hand side, it became obvious that the two sides of the screen had different ideas about which suit was trumps.
The Director took East and North outside to shoot them, but what ruling(s) would have been reasonable. If relevant it is highly probable that South would have bid 3♥ if he'd known about his partner's bid and, even if he didn't, then West would certainly have not let them play in 2♥.