I hate to report it, but it sems that the facts of the incident leading to the death of Corporal Fanningshire have strayed from the true course of veracity. Apparently, the wepon he was reported to be carrying in the photostat was not the Portable Flamegun as originally reported.
Apparently, Flameguns are doctrinally limited to use as anti-materiel weapons, and certainly not anti-personnel. Such a thing as roasting a man alive in a burning stream of naptha would be barbaric, and best left to the Hun!
No, the intriguing device carried by the late Corporal Fanningshire prior to his demise is properly known as a Caloric Ray Emitter. I am not sure just what those Royal Artillery and Royal Society chaps have created, but apparently it makes whatever or whomever it is used against very hot, very quickly, causing "extreme thermal blooms." Though what flowers have to do with this, I've no idea. In living things, these "blooms" cause the water within the body to boil away to steam, a sort of organic boiler explosion, I suppose. Sounds bloody dreadful.