The appallingly long newspaper casualty lists and near total destruction of Britain's professional army, the British Expeditionary Force, during the Battle of the Frontiers and the First Battle of the Marne are shown as suddenly appearing in the evening papers of the day Roland leaves for France in the winter of 1914 demonstrated by the heavy, warm, winter-weight coats and hats worn by Vera, civilians, and soldiers on the train and in the station. In actuality August and September were record-breaking hot months. These battles and the long casualty lists associated with them took place during August and September 1914.
When Vera is reading Roland's poem about violets, the "violets" shown both on the ground and in Roland's hand are actually pansies.
As Roland and Vera meet in late 1914 before he leaves for France, Aunt Belle notices that Roland is sick and she talks about how influenza is ripping through the troops and it's in all the newspapers "Spanish Influenza they call it." The earliest known case of what would only later be called the Spanish flu was in March of 1918--and reports of the plague were zealously suppressed in the press of the belligerent nations for fear that it damaged morale. The only reason the disease, which actually was first documented in Kansas, was named "Spanish Flu", was because Spain was neutral in the war and the Spanish papers were free to report cases, giving the wrong impression elsewhere that Spain was hit first and harder by the disease.
In several scenes set in the trenches early in the war the soldiers are wearing helmets rather than service caps. Helmets were not introduced until late 1915, and not in widespread use until early 1916.
When the Sister, a Scottish woman in her sixties, instructs Vera and another nurse to prepare two hundred beds by lunchtime, she says to them, "Move it, move it!" This would be anachronistic even in an American hospital at the time, let alone in Britain. It's only one step short of "Haul ass!"
Roland was killed in 1915, however, he is pictured fully outfitted in 1916-17 uniform and gear.
At 1:46 Vera puts some flowers in a vase, Sarah Bernhardt peonies and Pierre de Ronsard roses. While Sarah Bernhardt peony was created in 1895, Eden rose, also called "Pierre de Ronsard" was created in 1985.
When Edward is playing the piano by himself, his arms and hands don't move in conjunction with the notes that we hear.
When Vera is quickly walking out of the hospital, she runs into a nurse carry a basket. When she runs into her, a iPhone can be seen falling out of the Nurses hand and then can be seen in the mud.
About 20 minutes into the movie you see a small forest with yellow and purple flowers: On the right side of the screen some equipment falls to the ground.