When Alice reaches for the doorknob of her office for the first time the newspaper in her bag is sticking out the back. But when she enters the office the paper is still in her bag but now poking out under her arm.
The bonds securing Heather Graham, as Alice, to the table, are obviously inadequate. She could free herself easily. While it could be argued that Alice was playing along, later on she urgently requests Adam to untie her. So, the ineffectiveness of the rope undermines the impact of the crucial scene completely. To put it bluntly, the way it was done, makes otherwise bright Alice look far less than smart.
The goof item below may give away important plot points.
In the final cemetery scene Deborah is punched by Adam and falls to the ground. When we see her face next she has blood on her left cheek. In the next shot the blood is gone. And as she's being shot with the flare gun, the blood is now on her forehead.