Factual error: When Sarah leaves the hospital, she pulls out her drip, but does not bleed from the wound.
Other mistake: During the scene when Nelson takes Sara home after rescuing the puppies, she asks him in for coffee and he doesn't accept. After she tells him she will accept a ride the next morning, he agrees and turns off his car. One of his headlights does not turn off.
Continuity mistake: Keanu Reeve's secretary reminds him of a 1 o'clock appointment at the DMV. When he arrives, the clock on the wall appears to read 12:20.