My guess would be that as they were born a half-hour apart, they'd seem like identical twins. The passports would be forgeries, and would be fool-proof...except they'd have different dates of birth. AFAIK, identical twins can't have DOBs other than on the same day or adjacent days at the furthest. It was just a case that Fritz was seen to first and Hans was the second one to go through, aka bad luck :)
Now I'm not sure whether a cigar's coming this way...will it? won't it? :wacko: