Factual error: Early in the movie, Charles Carroll, identified as the last survivor of the 55 patriots who signed the Declaration of Independence, is portrayed as a Freemason. Charles Carroll of Maryland was not a member of the Fraternity.
Other mistake: When Abigail keys in her password to the preservation room, she only presses the keyboard 9 times including the return key. If "Valley Forge" was the password, she would have had to have used at least 12 keystrokes (including the return key.) And she never goes near the "L". (00:33:20)
Continuity mistake: When Gates takes out the champagne glass after making the fingerprints visible, the time on his watch changes from 9:11 to half past something. (00:38:45)
Factual error: In the scene when Ben, Abigail and Riley are on the tower of Independence Hall, they look at the shadow marking the secret place where the glasses are hidden. It is 3:20. The shadow of the cross is in the second third of the pillar. When Ian is on the tower the shadow has already moved to the top of the wall. As the others have left Independence Hall at 3:28 the shadow must have traveled the distance in about 4 minutes. This is far too quickly. (01:12:20)
Continuity mistake: In the treasure vault Riley stands in front of that emerald statue, and on its chest you can see a part which is not covered in dust. In the next shot the whole chest is covered in dust. The clean area coincides with the later placement of Riley's cheek, which means the first shot was actually taken after the embracing and implemented before. (01:50:45)
Factual error: Ben uses SuperGlue to show up the fingerprints on the glass that Abigail was holding. Once the fumes develop the prints they appear as being black, but this is incorrect. SuperGlue would actually make them white.
Factual error: In the scene in the Charlotte, the black powder would not burn without creating enormous amounts of thick grey smoke. And the barrels would never have exploded like that. Maybe one or two but never to that degree. More like a succession of explosions.
Continuity mistake: When Gates enters the password he has hit the keyboard 4 times "V A (actually the "Caps lock-key, as explained elsewhere) L L" but when we see the screen with the access code, there are only 2 stars hiding the letters. (00:42:35)
Factual error: To reveal the invisible ink on the back of the Declaration, Ben and Dr. Chase use pure lemon juice before warming the surface. This is best seen when Chase first test it out on the corner, where the Mason symbol is placed. Lemon juice is in fact also used as invisible ink (that you have to heat to make visible), and this procedure would have ruined anything written on the back of the document.
Revealing mistake: When Ben and Ian get the two different fingerprints from two different people, Mr. Ferguson [random security guard] and Abigail Chase, they are the exact same fingerprints. This can be confirmed on the DVD with pause and zoom. Moreover, the two scans show exactly the same emphasis/pressure on different regions within the print, with more light and detail on the left side and little in the center. (00:39:15)
Continuity mistake: After the Independence Hall chase, Ben tells Abigail & Riley to meet him at the car. When Ben arrives he is confronted by the detective, then placed under arrest, and in the background behind the detective you see Abigail & Riley standing on the sidewalk. In the following shots the positions of Abigail & Riley keep changing.
Other mistake: When Gates writes down the numbers from the back of the Declaration of Independence he forgets one number. On the document there are the following numbers: 11-6-6, 12-18-7, 14-3-7. Ben however only writes down 11-6-6, 14-3-7 and then keeps on. (01:01:10)
Factual error: When Ben and Abigail and Riley separate at Independence park Abigail and Riley could not possibly have exited the park and run right into the Reading Terminal Market. Independence park (where the liberty bell is housed) is between 5th and 7th and Walnut Streets, and Reading Terminal Market (where Abigail hides from the bald man) is at 12th and Arch street. At least 15 blocks apart.
Continuity mistake: When Riley and Abigail are running through the tunnel, trying to get away from Shaw and Viktor, we see Riley running into people and getting knocked around and held up. We see a lady in a red suit go by and then there are two men in suits, the one closest to the camera has a medium brown suit on, over the collar salt and pepper hair and glasses whilst the man farthest from the camera has a medium gray/blue suit on and very short brown hair. The next shot shows Riley trying to go between these two men only now, the one nearest the camera has a very dark charcoal suit on, short white hair and no glasses whilst the other man is wearing a black suit, has greyish brown hair and is much older than before.
Continuity mistake: Ben stirs a solution to make the campaign button fluorescent and tests the solution. He dips two fingers into the solution, rubs them against his thumb, then draws a smiley face on the tabletop. When he shines the UV light on the tabletop, there's a small, compact smiley face. But if you watch Ben very closely as he is making the smiley face, he draws the eyes much farther apart and he starts the mouth of the face between the eyes. The one he actually draws is not the one that is shown.
Continuity mistake: When Ian abducts Abigail, you see some one shoot at Ben and hit the hood of his van twice, but in another shot you do not see any bullet holes.
Continuity mistake: In the scene where Ben and Riley meet Abigail for the first time, Abigail's assistant ushers them into the office and the camera shows her walking out of the office. In the next shot you see the camera on Abigail talking to the two men. When the camera pans back to them, you see the assistant leaving the room again. (00:22:20)
Deliberate mistake: In the scene near the beginning of the movie where Ben finds the pipe and finds the message by rolling the pipe on the paper, the message is long and has symbols, but it is impossible for all of that to fit in the pipe. (00:12:00)
Revealing mistake: When the two vans are driving away from the Archives, Dr. Chase tries to open the door to escape. As the camera pans from her face to the door handle, you can see by the way her hair moves that the quarter-second sequence is run in reverse. (00:48:55)
Revealing mistake: When Ben, Abigail, and Riley are fleeing the National Archives, the window on the driver's side has been shattered by a gunshot. Although they are driving at high speeds, no wind seems to be entering the van to mess up their hair.
Answer: He doesn't simply assume "Beneath Parkington Lane" means beneath the church: Parkington Lane is the name etched on the tomb hiding the entrance to the tunnels. When he saw it, he naturally deduced what he had to do.
Sereenie