In other news, a manufacturer of cluster bombs said it could not be blamed for their use on civilians.
It's the perennial question; are manufacturers, sellers, those who allow them to operate, equally, more, or less, to blame than the people who use such things?
Pragmatically, the chain has to broken as close to the top as it can be. At the manufacturing end there will always be someone else wiling to step into their shoes. That's a never-ending game of whack-a-mole.
Deibert isn't wrong, but he's chosen to pick on the wrong target.