Why did your colleague not think you did well? Was it because they felt you had not responded forceably enough? Or because you did not wish to deal with the situation at all?
Im not sure to be honest. I managed to calm them down a bit to the point where they gave me their passports and the lady's green card. Then thats where my colleague took over and it turned into a slagging match.
In dealing with customers, particularly the irate kind, I use the four "F"s: Friendly, Fair, Firm and Final.
If you do all of these, you'll be amazed at how many times you can quickly defuse a difficult interaction with the public. If challenged like this, I would also offer a very brief, succinct explanation of why I'm asking. "Sir, I need to see the passport so that I can verify your identity and citizenship."
If there are alternatives to the passport, offer them. "Sir, I need to verify your identity. A passport is preferred, but I can also use a State issued drivers license."
You don't have be aggressive, but you do have to be assertive. There's a big difference between the two. While neither of the two statements above are aggressive at all, they also offer no wiggle room. Friendly, firm, fair and final.
Thanks, will definitely remember the 4 F's. Thats the approach that I took.