Or maybe clay is not his surface. Also Isaac Frost has a massive game and may have been "on" that day. Frost would have beaten Ben plenty of times whilst Ben was coming through the juniors, which can play on his mind?
O I didn't even realize that the tournament was on clay, that most likely was the reason then. But he has been playing a lot, he should relax for a week or two, do some training, and then maybe head to Europe or the States for some challengers.