Eben's eyes are wide, afraid and black, lacking in any sort of humanity. He opens his mouth to turn her away, shake his head, order her back and only manages a low growl, less that of a jungle animal and more that of a wounded eagle or bird of prey that caught the whiff of the wrong creature.
He'd thank god for his hyper senses if they weren't so damned confusing. She's human isn't she? but the way the crowd just moved...
When his mouth opens, Willow can perhaps note that his teeth are...far sharper then normal, "....No, no, stay away from me, I'm dangerous.."
This is the complete opposite of what someone wearing a "Sheriff's uniform" should be saying.