John Constantine: When I was a kid, I could see things. Things humans aren't supposed to see. Things you shouldn't have to see. My parents were normal. They did what most people would do. They made it worse. You think you're crazy long enough, you find a way out.
Angela Dodson: You tried to kill yourself.
John Constantine: I didn't "try" anything.
When Constantine manage to get the mirror through the window he falls on his back. To the right on the screen a chair lies on the floor beside a dresser. A few shots later when it cuts to Constantine getting up we can see the chair has changed position as its back now covers the opening of the dresser.
Stay after the credits. There's an additional scene where John goes to visit Chas' grave and leaves a lighter, then as he's walking away you see Chas with wings and he flies up into the sky.