Hmm, I really dont think there is any reason to think the verocity of ejaculation is important at all. provided ejaculation places semen in contact with the cervix, that's as much as it can do. Fertilisation takes place higher up.
And in response to Torch, I was speaking only about what was possible. I never said it was probable, of course fertilisation under suboptimal conditions is enormously unlikely, but it's still possible. That's the point.