I believe there were three awardees in the category:

Joel Fajnor for Kung Fu Panda: Legends of Awesomeness,
Ernie Gilbert for T.U.F.F. Puppy and
Christophe Vacher for Transformers: Prime.

I don't believe it's possible for the award to be a case of being the only person in a category, in that these three people have specifically been chosen out of everyone in animation for their individual achievements. All three are winners - each of them gets an Emmy.