Roger and the Mexican Train

Our friends Livia and Roger were round for the afternoon and evening, including dinner and our non-Swedish mince pies and Christmas cake.  The weather was not good for driving, with rain falling onto a deeply frozen road and immediately freezing, creating hazardous conditions, even by Swedish standards, so we were extra happy they still made the effort to get to us.
Jan cooked a delicious vegetable curry and I baked sourdough naan and fixed the rice.
Later in the evening we played Mexican Train dominoes and Roger won. Could this be because as the driver he had remained alcohol free, while we others had drunk a little mulled wine, wine, and beer?