Those two were not lured by the voices of witches/familiars, which is the case for victims with witch kiss. They just happened to be in the battlefield at the wrong time.
Depending on how a witch do so. Some people may fall astray accidentally or if the Witch do so... But if the witch really put a witch's kiss in Homura,then she should committed suicide. Also it's possible that the witch is in that place where Homura was walking.
I should point out that only those with potential can see QB. Homura could easily see him when she was attacked. Hitomi couldn't see QB when he is hanging with Madoka.
darth_tohru said: QB is a liar. I bet he tells every girl she's got potential.
QB never lied. He just makes up incomplete truths and omits information. Then falls back to his "you didn't ask" excuse. He's a bastard but a clever bastard. Unfortunately.