Naval battle: Bug or just me?

Hi all, I'm wondering if this is a bug or maybe I just don't understand how naval battles work. I had a battle as Austria against Barbary pirates. I had 3 Brigs they had 9 or so galleys, I was also being reinforced by some other country, can't remember but they also had 3 brigs. So the whole fight starts off very well, 2 of the galleys rout after the first volleys are traded but then it gets weird. One of my brigs just surrenders. It was close to the line of galleys but they never dropped below steady as far as morale. It hadn't taken any major damage either and had only lost 2 or 3 men. I figured I just missed something and as the battle went on ANOTHER brig surrendered under the same conditions. And finally after 2 or 3 minutes, my admiral surrendered. I was keeping a close eye on him the whole time at this point and he had taken a few stray hits (no broadsides, remember I'm fighting galleys) but the masts were still up and they had lost maybe 10-15 guys. Their morale was good, can't remember what exactly it was at but it was above steady. So now I'm looking at an empty unit list and the battle is still going with my ships sitting there unmanned surrounded by their sailors. NONE of the AI ships had this problem only mine, so was I doing something wrong? Or is this a bug some of you have experienced? Thanks for any input!