How had Armand escaped?

Percy sends a note instructing Armans and the other to go down the cliffs and meet the boat that he will signal. Percy is disguised as the Jew, the Chauvelin has threatened his men they aren't to leave until they see Percy, and the soldiers follow his instructions, thus, allowing the fugitives to go free.

“Zooks!—then I carried out my little plan: that is to say, at first I only determined to leave everything to chance, but when I heard Chauvelin giving his orders to the soldiers, I thought that Fate and I were going to work together after all. I reckoned on the blind obedience of the soldiers. Chauvelin had ordered them on pain of death not to stir until the tall Englishman came. Desgas had thrown me down in a heap quite close to the hut; the soldiers took no notice of the Jew, who had driven Citoyen Chauvelin to this spot. I managed to free my hands from the ropes, with which the brute had trussed me; I always carry pencil and paper with me wherever I go, and I hastily scrawled a few important instructions on a scrap of paper; then I looked about me. I crawled up to the hut, under the very noses of the soldiers, who lay under cover without stirring, just as Chauvelin had ordered them to do, then I dropped my little note into the hut through a chink in the wall, and waited. In this note I told the fugitives to walk noiselessly out of the hut, creep down the cliffs, keep to the left until they came to the first creek, to give a certain signal, when the boat of the DAY DREAM, which lay in wait not far out to sea, would pick them up. They obeyed implicitly, fortunately for them and for me. The soldiers who saw them were equally obedient to Chauvelin’s orders. They did not stir! I waited for nearly half an hour; when I knew that the fugitives were safe I gave the signal, which caused so much stir.”