NEDIVER, my point was that the Meg is not the only unit that does inject O2 in the inhale side. Your question was about if this type of design, as encountered in the Meg, may lead to a situation where one inhales a pure slug of O2, as you put it. I've tried to help by pointing out another manufacturer's answer to the question, which, as I was saying, is lacking hard numbers as supporting evidence - as your quick math shows. They basically say: "it's a non-issue, believe us" . This seemed relevant to the question.