The problem with letting non-females participate as females isn't that they might run 1:41 - as Noakes said - it's that many high school guys can run world class female times. If you were to take his logic to its conclusion that Bolt's genetic differences over his male opponents are no different than genetic differences attributable to gender than we wouldn't have female sports at all - we would just have females attempt to compete with males. The result would be that there wouldn't be any females in Olympic sports - is that what Noakes wants?
I feel bad for people who are intersex - not only in relation to sports - but, just daily life. It must be a very difficult thing, but that doesn't mean that they should be allowed to compete with females - the advantage is too great.