Cañon City - S12-E1
Continuity mistake: Sam and Luka are driving to Colorado, presumably in a hurry, to try to find her missing son, Alex. While their driving in the daytime, you can notice inconsistencies in the traffic and road. They are driving on the interstate, but getting passed up by semi trucks. The trucks are not slowly passing them either. It's almost as if they are stopped and the trucks are whirring past them. Then in one shot you see a car change to the left and start to pass, but when the camera angle changes, you see Sam passing up a semi truck at a high rate of speed. A moment later, as their still chatting, an exterior shot of the car shows them changing to the left lane to pass a truck, however the lines in the road are yellow, meaning they are not on the interstate anymore.
Other mistake: At the beginning of the episode, Abby is almost run over by a man driving an SUV. They exchange words and then Abby throws a supposedly full cup of coffee at him. The cup of coffee bounces off the seat of the man's car and it is obvious that the cup is empty.
Continuity mistake: While Pratt and Ray are giving chest compressions, the victim points to a "pain" chart and leaves a smudge of blood. But in the next shot, the blood is gone.
If Not Now - S12-E11
Factual error: The male patient tells ER doc that "Six years ago, l find out l inherited the Philadelphia chromosome. Ran on my mother's side of the family. L never knew. Screwed by genetics." The Philadelphia Chromosome, the cause of CML Leukemia, is not inherited. It occurs spontaneously in an individual, usually due to chromosome damage caused by radiation, and cannot be passed on to a person's children.
Answer: Take care of your dad.