Question about Lexington Letter

I see a lot of people debating here that Lexington letter shows that the numbers are more than emotions. Some even say that it is about cryptography, corporate espionage, etc., mostly based on the Lexington Letter.
I read the Lexington letter and it just says that the time was close 2:30 PM and 2:32 PM. That's the only basis to connect the two events (Peggy finishing it and the truck blast). I initially thought that the truck blasted in "Lexington Ave" and that is the main connection. But no, its just the time. It just seems to small a connection.

So, question: Is that the only thing connecting them or did I miss something? If time is the only thing, it seems like a major overreaction from Peggy.