When I was there, all you needed was a laminate with a barcode. They scanned it in line and as long as it was valid, you got your food. No questions asked. I was only there that day though so maybe its different normally?
You need your laminate with a real barcode on it. Not a fake one. And the staff know their shit; they wouldn't have ever been able to get catering.
They're pieces of shit who stole from the tour by sneaking in.