What clues do we have that Domingo Salvador is not actually drunk in Part Ten?

While he hiccups and behaves foolishly, it soon becomes clear that Domingo Salvador has a very clear message for the children. His message is that the children are close to Fort Mose and that they should, in fact, continue on their journey. He tells them of the freedom that awaits, how they can join the Catholic church and the Spanish government to attain their rights to freedom, and exactly which way and how far they should travel. When he needs to make a clear point, he looks them straight in the eyes for emphasis.