Yes, it is probably better to quote the info as being from Jim. I wouldn't have one issue in the world with that. We live in a crazy sue happy world for the silliest things, so OK.
That being said, why on earth didn't Dee approach yourself or Jim? She could have pulled you aside and said helpfully, "Just to cover our tushies, here's a head's up. You should always tell the students the recomendations were from "proper person A" or "proper person B".
The fact that she didn't let you know directly, or go to Jim if she felt she had real concerns, tells me you need to keep an eye on her. She went out of her way in the workplace to make sure that you, who have been appearing competent and productive up to now, got a tiny blip on the radar higher up for this little faux pas in wording?
To me, she felt you were getting a bit too big for your britches and tried to take you down a peg. It may have been a tiny peg, but she still got the satisfaction of getting you spoken to.
She should now be on your radar to watch for future occurences.