There a few articles and at least one video out on this. I am always skeptical. I don't think the powder taken out of the bore was original to the cannon's capture or salvage. In the photo I saw, it looked perfect, like right out of a Goex can. The cannonball had no corrosion, very unlike the surface of either cannon shown in the video. Also the fact that the wadding was cotton bothered me. I think there's a good chance the cannon was loaded by some pranksters for firing on some holiday in the 20th C. while the cannon was still outside on display. The fuse went out, or more likely there was a pool of water in the cannon which prevented ignition and the pranksters went home to sober up. My theory anyway! If the powder were original to the time of salvage, the bomb squad made an historic error in failing to preserve some for analysis by the historic/scientific community.