That made no sense with Rosita (Spoilers)
She was apparently bitten on the back, yet in the scene where shes in the middle of all the walkers shes wearing thick layers of clothing and a big coat with a hoodie covering her body and her upper back area entirely, there was no way a walker bit her that perfectly in the back through those layers of clothing and not tear the clothing or have any blood on her at all after.
The bit was just magically underneath her clothes.