A/B in Directed Studies!

I was just wondering if there was anyone out there who got a A/B in directed studies. I asked the prof. and she said she doesn't know and the grad student I was working under gave me an A/B. I ended up working for him another semester and got an A in that later semester and even got a LoR from him.

So does getting an A/B in a directed studies course look very bad? It is a 6 Credit Biology Directed Studies course so it factors into my BCPM GPA