My heeler would still piss in the house sometimes up to 2. He wouldn't let you know he had to go out then walk through the house while peeing.

First year can be pretty rough to get training to stick, if you're familiar with dogs (especially very active breed ones like german sheps) then you're probably right about the little beasty though. Maybe just try to be as consistent and simple as you possibly can? Even pugs can be trained with enough patience, and they're physically and mentally retarded to the point of barely being able to breathe.