The Best In The Business: Castle Siege

Bad Jim drives the big car down yet one more hot, dusty, Mexican road. Once again he had been followed, by people that he had hired. However, the hired people have done the job they were paid for and they're now on their way back to the US border. However, they have left behind them several hidden supplies of fuel and also have hidden a powerful motorcycle of the dirt bike variety.
Bad Jim finally spots the village that he has been told to look for.
The village is just a small cluster of adobe buildings, mainly houses, a few businesses and a few large warehouses, where the farm products of the surrounding farms can be stored for eventual sale.
Bad Jim parks the car outside a cantina, which is maybe the most prosperous looking of the village buildings. Bad Jim gets out of the car and walks inside the cantina.
Several hard faced men await Bad Jim, inside the cantina.
Perhaps the oldest of the men tells Bad Jim, “You have been granted safe passage in and out of this place. The reason for that safe passage is that you claim to have a way that our people can invade the house where Linda Jones lives. How is it that you have such a way?”
Bad Jim asks the man, “Have any of your people been inside the house where Linda Jones lives?”
The older man thinks for a moment and then says, “Of course, none of our people have been inside the house where Linda Jones lives. Of course, we know that you have been inside the house. You then claim to have discovered a weak point, that we can attack.”
Bad Jim lectures, “It's a big house, set well back off the main road. It's a lone house surrounded by high, strong walls, with iron bars on the windows and gates. Just outside the strong walls are fairly deep ditches. The place is a fort, a castle. It's easy to defend and hard to attack, at least if the attacker uses conventional techniques.”
The older man again thinks for a moment and then says, “You then claim to have discovered an unconventional means of attack that will work?”
Bad Jim lectures, “In my business it's important for me to maintain myself in top physical condition, at all times. Thus, I asked that I be allowed to work out, while I stayed in Linda Jones' house. While I worked out, day by day, I was insulted by the hombres who guard the house. I then asked if I could be permitted to run around the outside walls, to escape the insults of the guards.”
The older man again thinks for a moment nods and then says, “Yes, our people observed you doing just that. There are deep ditches with berms that prevent the viewing of the ditches or the bottom of the walls, from outside the walls.”
Bad Jim states, “The view is blocked, unless a man runs just outside the berms. Then he can see the ditches and the bottoms of the outside walls.”
The older man again thinks for a moment nods and then says, “Yes, that might provide some useful information. The question is, what useful information?”
Bad Jim smiles and asks, “Do you or any of your men know how they attacked a castle, in days of old?”