American Express Software Engineer interview questions

The interviewers arrive to the lobby 15 minutes late. There were 3 interviewers who each came up with their own coding questions, however they were attempting to come up with questions to intentionally stump the candidate. They did ask for me to whiteboard out a whole class, which wasn't really a challenge, however one interviewer in particular called out some syntax in a for loop that I created saying it was incorrect (claimed I used the wrong brackets), where I was quite surprised that a senior developer did not know the correct brackets to use for a for loop as his teammates later said he was incorrect.