Yes that is not brain matter by any means. If that rat would have hit brain, your snake would be either dead or having some major issues right now.
Neosporin with out pain killer in it will work right now till you are able to get your snake to a vet.
Also I'd like to say that feeding live doesn't mane bite occur often. In the 3 years I've been feeding live, 1 of my snakes got bit (or more like the rats top tooth snagged my snakes side while it was trying to get away/gasp for air). Been feeding live for over 3 years now every 7 days with a number of snakes here and there. Feeding live in perfectly safe when done right and monitored.