I remember Elliot's dad saying something similar to the process server when he was looking for Elliot. I guess they do not realize that your responsibility for you children does not end when you stop sleeping with their mother. Also, I think we now know why he is so behind on his support...the money is going up his nose. I am sure the captains get tested before they go out to see, but maybe Elliot has methods of getting around the tests (buying clean urine)? At this point, I would not put it past the guy.