In the first place, having a "veto" right is the thing that is where the loophole began. Sooner or later, I believe it is inherently prone to centralization power.
As the allegation arises, this kind of problem is tricky to overcome if the communities of the project itself are not strong and united. Even if they are persistent toward keeping the project/community stable and sustainable, hard-forking the project is the only way to go if the alleged developer itself does not cooperate.
They delivered on non-trivial software innovations, but it's sad to see human ego and a centralization of power take over again.
The hybrid pow/pos model is experimental, and so does Bitcoin itself. If the system/project design can not sustain the longevity of a decentralized consensus or processes, there must be a flaw that deem the project not to withhold the decentralization.