When the Sgt. returns to the room to find Rose Marie gone, he wakes the manager for entry, when the manager enters the room he has a noticeably different night shirt on than before he entered, one has vertical stripes the other horizontal.
After the store clerk (Lucien Littlefield) tells Marie (Jeanette MacDonald) to go to the Mounted Police she wanders through the village and sees a poster stating that her brother Jack (James Stewart) is wanted for murder. The poster gives Jack's height as 6'1". Shortly afterwards, she again sees a copy of the poster listing his height as 6'1". Shortly after that she sees a third poster where Jack's height is listed as 5'8". (James Stewart was actually 6'3" tall.)
When Sgt. Bruce is taking Marie de Flor across the lake in a rowboat, he paddles only on the right side. The couple are in a canoe. It is common in canoeing to paddle on one side employing a J-stroke--adding a lateral slip to counteract yaw.