It's pretty unlikely that an injector is bad. Spica injectors are mechanical and operate under 400 psi of pressure and almost never go bad.
How do you know there's no fuel getting to the #1 cylinder? How did the mechanic know? It's common that mechanics that are unfamiliar with the Spica system, blame it first then send you away with a shrug of the shoulders.
I suppose it's possible that you broke a rod assembly in the injection pump, but that's very unlikely also.
I suppose you could loosen the nut that holds the pipe on the injector and see if you're getting fuel through the pipe. Keep in mind that on each pump stroke, the amount of fuel pumped is pretty small. Past that you could remove the inspection plate on the side of the pump section of the injection pump, rotate the pump and make sure that the #1 plunger is indeed moving up and down.