One against whom there was no official complaint (line 2)
The Unknown Citizen isn’t the only passive person in the poem. The speaker is also quite passive, or maybe passive/aggressive would be more accurate. The speaker never gets excited about anything. He can only delivered compliments in the negative, by saying what the UC didn’t do wrong, rather than what he did right.
Yet he wasn’t a scab or odd in his views, For his Union reports that he paid his dues, (lines 9-10)
These lines have a nonsensical connection to one another. The speaker deduces that the Unknown Citizen must not have been a scab or had strange opinions simply because he paid the regular membership fees for his Union. The point of a Union is to protect the rights of the factory workers, but, if left to their own devices, they can just suck up people’s money and give back nothing in return.
And that his reactions to advertisements were normal in every way. (line 15)
The Unknown Citizen doesn’t act, he reacts. It’s almost as if he were the subject of a scientific experiment, where things were being placed in front of him to see what he would do. "Hmm, I think I’ll buy a frigidaire." Success!