Pluralism
I know this is nitpicking at it's worst form but... the saying, "The debt that all men pay", is uttered more than once by Ben and Patrick Gates when trying to figure out the key to the Playfair cipher and by Thomas Gates when telling his son, Charles, the key. But in the diary, it is written, "The debt that all men pays". So, that's two mistakes. First by saying men, plural, you need to say pay, singular. I know... nit picky, but what all of the Gates say isn't what's written in the dairy, but is grammatically correct.
Second: when Ben is trying to get Abigail to at least run an infrared scan on the missing Booth Diary page, he says that she can have the Boston Tea Tables. In reply, she says, "Both of them?" What part of tables, plural, did she not hear?
OK, English Teachers, where am I going wrong? No replies from the peanut gallery. I love this movie and I'm not picking it apart for ANY reason... just a couple of things I noticed, so save your sarcasm for your dog, or wife, or whomever you deem your best friend.