When Sophia ( Kiersey Clemons) comes back to life and the cleaning crew is getting closer, she is barefoot. When Ray (Diego Luna) is carrying her out, we can see that she has her shoes on.
When Courtney flat lines and the two struggle to resuscitate her, Sophia pages Ray and the scene goes back to Sophia trying to revive Courtney, behind Sophia the EKG machine is clearly visible with a pulse of 0 beats per minute, but the line is showing a very strong and regular heartbeat instead of the flat line you would expect to see.
When Ray meets Jamie as he is getting off his motorcycle, a Toronto streetcar in the background changes to a bus in consecutive shots.
After Sophia's resuscitation, Ray carries her to speed up their escape from the cleaning crew. In one scene Sophia's head is on Ray's left shoulder, in the other scene, it's on the right.
When Courtney went in for flatlines, she mentioned no metal allowed inside the room as the scanner contains magnet but there are laptops, and mobile phones and other medical equipment which can be attracted by a strong magnet.
Marlo killed a patient due to negligence and then covered it up. No reputable medical school in the world would simply put a student on probation for committing acts of that magnitude.
When Courtney fell off the fire escape onto the sidewalk she didn't have her phone on her, as she dropped it while filming (getting dragged out) So the phone wouldn't have been at the morgue with any of her other possessions.
Defibrillation pads are only effective when in direct contact with the skin. Clothing can cause the electricity to flow across the chest not through it as it is supposed to. The depicted defibrillation in Flatliners bears very little resemblance to real world scenarios.
A written statement would in no manner absolve the residents from deaths performing the "flatliner" experiment. Courtney writing one after stealing the Propifol to perform the experiment on herself would simply make the people assisting her complicit with several crimes, up to and including her death.
In the morgue when Marlo calls Courtney's cellphone, it shouldn't be able to ring because of a dead battery. Later in the movie, in the cafe we see that Courtney never stopped, and dropped her phone when she was haunted by her dead sister in her own house. So the phone never stopped filming until the battery died.
Courtney's phone shouldn't necessarily have been running out of battery power if she didn't stop filming. Many phones will run out of internal memory way before they run out of power when filming in full resolution, especially when the limited internal memory hasn't been expanded with an extra SD memory card. Furthermore, most phones still use the FAT32 file system, which limits the size of a single file to 4GB max. These and many other scenarios could have caused the phone to stop filming after 5 to 15 minutes and after that switch to the default inactive state that could keep the phone running for a few days when not used.
Courtney's phone shouldn't necessarily have been running out of battery power if she didn't stop filming. Many phones will run out of internal memory way before they run out of power when filming in full resolution, especially when the limited internal memory hasn't been expanded with an extra SD memory card. Furthermore, most phones still use the FAT32 file system, which limits the size of a single file to 4GB max. These and many other scenarios could have caused the phone to stop filming after 5 to 15 minutes and after that switch to the default inactive state that could keep the phone running for a few days when not used.
As per the director, Marlo's car does not have any license plate nor temporary license plate in the rear.
When Sophie picks up the Rubix Cube and starts to solve it she just spins it randomly and sometimes moves a section then reverses it to the same position. Some of the colors also change when not in view of the camera.