Plot hole: In the scene where she goes to her house after escaping there is no police tape on the front door even though it is a crime scene. Earlier the police searched and taped her office - it only makes sense that they would do the same to her house.
Visible crew/equipment: In the scene where Halle Berry is going to talk to her lawyer, when she goes into the room you can see a microphone on top of the screen.
Plot hole: In the shower scene when Miranda is being cut, everyone in there, including the guard, sees her getting the cuts out of nowhere. Yet they all say, she did it to herself with a scalpel although one was never seen or found. Don't they think if she did it to herself, they would've seen it?
Plot hole: There's no way the guards couldn't see Miranda in the swimming pool. For one, you can see clear to the bottom of the pool. And their flashlights shined clear to the bottom. And when she emerges, she screams. They should've heard her since they just exited the pool area.
Continuity mistake: When Halle starts screaming while busting through the barricades, her windshield cracks on the lower driver's side. After the car stops there's no crack anymore. (01:04:40)
Revealing mistake: When Robert Downey Jr. is taking Halle Berry's blood pressure, the needle doesn't move as he pumps the hand inflator.
Continuity mistake: At the beginning of the movie when Halle Barry is talking with her husband in his office, every time a shot cuts to him sitting at his desk, the way items are arranged on the desk changes.
Continuity mistake: When Miranda (Berry) took the guard's car and skidded to a stop by the sinkhole the front passenger wheel was angled toward the driver. A few shots later as the camera pans away from the car the wheel is straight. (01:05:00)
Continuity mistake: In the scene where Miranda escapes and goes back to her house, we see flashbacks to her husband's murder, including one of Miranda in the bathtub filled with water stained red from blood. When the flashback ends and we return to the present, the tub is spotless, even though there should be at least remains of blood there.
Audio problem: In the scene where Miranda is at her home looking at the photo of her and her husband, she says "why me?" but her mouth does not move. (01:10:55)
Audio problem: After Halle Berry escapes she is driving with two hands on the wheel - but the engine sounds indicate she is changing gears, and the gear stick is seen in previous shots.
Plot hole: You are the police looking for an escaped madwoman who killed her husband and is in denial. Where is the first place you would look? If you said her house, congrats, you are smarter than the cops in this movie. Yet Halle Barry manages to spend the entire night there (she escapes just after midnight) crying over pictures without so much as a knock on the door.
Revealing mistake: When Halle Berry is speaking to her husband about Chloe, she mentions the medications she has given her. She pronounces Haldol like "Haddadol." As her character's a doctor, she would know the proper pronunciation of the medications. (00:06:15)
Revealing mistake: Rain doesn't fall in a circle pattern as seen, revealing the use of a rain maker.
Answer: The blood is not from Miranda; the drop of blood is a sign from the "dead girl" to tell Miranda that she should go to the place in the pic. Miranda goes the next day and that's how she finds her husband was a sadist.