"And it's empty - there's no TNT!" - Invaders received shells without explosives.

There's a story from WWII about an injured British bomber making it back home and discovering unexploded 20mm rounds in its fuel tank, that certainly would've destroyed the plane had they exploded.

When they looked into it, they found the shells were empty, with a note in one of them written in Czech, that said, "This is all we can do for you now. Using Jewish slave labour is never a good idea."

Seems like maybe this has happened again. Despots never have the level of control they imagine.