Fortunately for the person she bumped into, Sarah didn't make tactile contact with them. So the person was unaffected. But the next person that Sarah made skin-to-skin contact with would change.
Meanwhile, back at the food court, Jon and Yuki ordered some hot dogs at The Doggie Stand and sat down at one of the tables. Shortly later, they were eating and talking, having a good time. As they did, Jon began to change even more. But no one, not Jon or Yuki or anyone else, noticed.