The programmer who implemented the code? Do you think they thunk these tricks up? They was just following orders.
The manager of the programming team, who set these tricks as things that needed to be implemented? Again, just following orders.
The "Cxx" Title people who directed that there be "some protection" in some way that got implemented as what we see? Did they specify these measures? Did they say "it should break if serviced by a competitor?" Unlikely. Thye wouldn't know how to be that specific, probably.
Some middle manager, maybe a committee meeting, sketched out a "DRM" scheme with the specifics? What do you imagine that meeting looked like? "We've got a directive to secure the systems from outside tampering, what does that mean in terms of how the machine behaves?" Or does that bring us back down to the engineers again?
... the responsible part here isn't a person, its the company as a whole. Just as it took the collective efforts of everyone to make the train, it took their collective efforts to make it wrong.
Corporate Death Penalty; perhaps. make it plain that we will no longer tolerate sill shenanigans like this.