Who was stabbed by a German pilot in the epic war film '1917'?

The film 1917 is a 2019 epic war film directed, co-written and produced by Sam Mendes. The film stars George MacKay, Dean-Charles Chapman, Mark Strong, Andrew Scott, Richard Madden, Claire Duburcq, Colin Firth and Benedict Cumberbatch.

During the First World War in April 1917, the German army has pulled back from a sector of the Western Front in the north of France. General Erinmore briefs two young British soldiers, Lance Corporals Tom Blake and Will Schofield. They are ordered to hand-deliver a message to the Second Battalion of the Devonshire Regiment, calling off their planned attack, which might cost the lives of 1,600 men including Blake's brother Lieutenant Joseph Blake.

Schofield and Blake cross no man's land to reach the abandoned German trenches. These turn out to contain tripwires, which a rat triggers. The ensuing explosion almost kills Schofield, but Blake digs him out. They arrive at an abandoned farmhouse, where they witness a dogfight between three aircraft. The German plane is shot down and plunges into the farm in flames. Schofield and Blake drag the burned pilot from the plane. Schofield proposes to mercy kill him, but Blake has Schofield fetch water for the pilot. The German pilot stabs Blake and is shot dead by Schofield, who comforts Blake as he dies, promising to complete the mission.