Japan is a hugely superstitious country. If you put a shoe in their washing machine, they'll have to get a new washing machine because it's "dirty". No amount of immunoassay tests or disinfecting could tell them otherwise - and that's not to say they don't have faith in technology.
Throw herd mentality (DUMB herd mentality) in there, and I see this as something that can really happen. Don't forget that we do have a real ghost stirring things up in the first place.
I can't ever imagine myself being a dumb-ass herd person, partially because I'm so detached with everything that I actually won't give a shit enough to tip me over the edge. Another big part is my fatalist mentality (or perhaps it's just a glorified form of laziness) where I just say something can't be helped instead of deciding there must be a way out of something (and then imagining or coming up with a BS way).
I will go ahead with herd mentality if I see it though, assuming that it's as powerful as the one we saw. The reason there is because there's nothing you can do to stop it (I'm not as optimistic as Teichi, orresourcefulfortunate enough to have a barely-dressed Yuuko with me). If you kept insisting that they're wrong, they'll just come up with a BS reason to get rid of you.
"You're her comrade, aren't you?" /kill