I recon it’s more likely the 3 bottles of cheap French supermarket wine they downed the night before....It's like a perennial weed. They come up every year. Normally accompanied with a sad tale of the poor gassed family so worried about leaving their life savings at home they took it with them in a shoe box hidden in the wardrobe along with the diamond tiara that had been a family heirloom, all now taken by those dastardly thieves,
I can only assume that the gas used was laughing gas ....