Strange Guest List
When Steven Price is in his office writing up a new guest list, notice the first two names on the list: Mary Seward and Vladamir Tymrak. Later, Price says he didn't invite these people, he said he invited the most desperate people who would do anything for money. This is strange because to invite Mary Seward, he would have to travel back about 150 years, AND stop her from murdering her husband. To invite Vladamir Tymrak, he would have to travel back to the 17th century and stop him from becoming Vlad the Impaler, better known as Dracula.
Impossible Sunrise
At the end of the movie when they are out on the ledge and are watching the sunrise, notice the sunrise is over the water which is to the west. The sun rises in the east so there is no way they could have been on the west coast.