When Hannah and Dani are talking, there is a vase with flowers on the table in the foyer.
When Dani is searching for the children whilst playing hide-and-seek there are no flowers.
When a Hannah & Jamie are watching the kids in the garden Jamie's cigarette lighter alternates from a cheap blue BIC lighter to a brass zippo lighter.
The Key Signature on the classroom board isn't a real one. In fact the treble and bass clef aren't even in the same fake key.
At about 3:41, Owen is shown cooking sausages using a fish spatula. Owen's character studied cooking in France; a trained chef would not use the wrong cooking utensil in prepping a meal.
The continuous American school bell used in the classroom scene is not used in the UK.
Flora answers a wall phone in the kitchen. However the phone is a North American style phone, not a UK one.