Methane is CH4. The C is for carbon. Come on people!
You left out the last part: "...does not rely on either carbon or oxygen for respiration". I'm no chemist nor am I an expert in exobiology so somebody who is may feel free to educate me if I' wrong here. Having said that, the way I understand it a hypothetical methane based life form on Titan would use complex hydrocarbons as an energy source by reacting them with hydrogen like for example reducing ethane and acetylene to methane and it would consume i.e. respire (inhale) hydrogen for that purpose. So the statement is correct, these Titanian life forms would neither respire (inhale) Oxygen nor a carbon based gas like life forms on earth do, just the hydrogen that is disappearing when it hits the surface of Titan. What you would expect to seen if such life forms existed on Titan. would be an unexplained disappearance of hydrogen (check) and methane being produced (check) with fluctuations in both as populations of these life forms grew and shrank for whatever reasons (seasons, radiation, predators,