So it's not okay to spray someone with spittle (coughing) but it is okay to make physical contact via a known disease vector (mouth) on the face of the recipient?

I grew up in a "kissing" culture. Hated it then, hate it now. I don't even like to shake hands.
I wouldn't go running out of a room, but I certainly would be annoyed if this incident happened to me. Who knows, maybe this woman suffered some form of sexual abuse previously, maybe she has sensory/attachment/some other kind of mental condition. I am not one to judge.
It also goes both ways. It's not just the woman that needed to be aware of local custom. I would certainly be a little more aware of how my bizarre cultural introduction would come across to a person not of my culture and act accordingly. Maybe a "in our culture it is tradition to kiss one on the cheek as a token of greeting" or whatever.