This provider just had to take one step backwards to be out of the reach of the child that was hitting her. The child was wrong to hit anyone and should be corrected but the adult was in charge of the situation and handled it wrong.
I would tell your good friend the director that I would expect that she informed the parent of the incident.
A quick Question??? Where was this 16-17 month old baby that he could reach her nose? Was he spending the day in the crib? You said hitting not "the baby threw some at the provider".
I watch my great-grandson several times a week and there is no way he can reach to hit me in the nose if he is on the floor or in the playpen. Perhaps she was bent over and got "socked" that would change my answer.