The seagulls, the ones in Darkest Hour. Not just length of the seagull noise segments, but the fact that it doesn't sound like seagulls over the beaches of Normandy, if that's what it's meant to be. White cliffs of Dover, maybe, but that's definitely a load of seagulls on cliffs, you can hear the echoes. I speak as someone who is used to the seagull-infested shores (including cliffs) of North East England.
It's meant to be Dunkirk at the start and Normandy at the end. I think Bruce didn't realise that maybe people might interpret it as Gallipoli at the start.