While in the cell, Hayley's hair changes between shots after she lets it down, shortly before she lies down.
Right after Hayley pushes Jake into a toy bin, you can see that many sprinkles have fallen off of her face. But more are there when she opens the door the Zylork is contained behind.
After the book with the instructions for the antidote catches fire, Mr. Stockley grabs a fire extinguisher. When the extinguisher first starts spraying, it is a Carbon Dioxide type, as shown by the large nozzle and the cloud of CO2 that comes out. But later it somehow turns into a foam spraying one, as shown by all of the foam on the walls, furniture and Mr. Stockley.
As Hayley is dragging Felix into the elevator, you can hear a man's voice say "sorry". Possibly an off-screen crew member?