In the first scene with Parker, she is seen taking two selfies, wherein the audience sees her taking the pic, then the pic itself appears on-screen beside the "live" footage of her. The second selfie pic features a lock of hair fully crossing the middle of her face when the footage of her taking the picture has the lock of hair falling down the right side of her face only.
Set in April of 2020, Parker (Gideon Adlon) is showing being administered a rapid COVID test. The first rapid COVID tests were not available until May of 2020, and these were only available in healthcare settings. The first in-home rapid COVID tests were not available to the public until December of 2020. While it is possible that the killers took one from the hospital, a direct-read test that did not require laboratory equipment was not available until August of 2020.
In the opening scene, when Tyler arrives to his apartment complex, one of the camera crew members can be seen in the car window reflection.