Of course Galen couldn't very well spill this information. He hadn't gotten to be president by simply going around spilling information that was supposed to stay hidden. No, Galen had chosen (very wisely) to keep this information under wraps. There was so much he didn't understand about that. Anyone on the outside who chanced upon this information would assume a lot of things. One of those being; Val had hired some outside mercenaries to help his inept nephew.
But then again, there wasn't any way to find out for sure. Hence, his decision to keep it under wraps. It wasn't really a good idea of meddle with the Marquis' family affairs. It also wasn't a good idea to keep information hidden from the princess. After all, he didn't really lie. He just kept part of the truth to himself till he could find out the whole picture. Lying to a royal was a dangerous gambit. But Galen had been in this game too long to not know how to play it.