This is another thread about a quirky scene when Columbo is in a public setting (see the Exercise in Fatality thread I started). In Blueprint for Murder, in the scene when Columbo goes to inquirer about a permit, some of the same people are in lines in two different rooms. As he is leaving the safety and inspection room I spot at least two people standing in line who are also in line in the engineering room. One is the guy in a yellow shirt holding a grey coat. The other is the guy holding a black coat. Since by every indication Columbo went immediately to the second room, unless these guys had dopplegangers them being in both rooms would not be possible by real world standards.