If you all believe AmEx would put their discovery mechanism in the email, you would be mistaken.

Their internal system picked up on some behavior based on some undisclosed rules, and put the account into a queue. A human takes a look, decide that the computer was right, and then grabbed the boilerplate template with 2-4 pre-approved reasons, and picked whatever was closest to what the analyst decided to be the abusive behavior.

Over time, they can improve those rules based on new understanding, but still use the same bad template language. They can even run the rules on past transaction history at any time.

So to the folks that says "it hasn't happened to me yet!" Computers are like elephants.