Vitalik Buterin acknowledged that common‑mode failures can make both Stage 0 and Stage 1 less secure than the model suggests

Quotes that support claims

However, Buterin emphasized that this model is not without its imperfections. In the real world, there are always additional risks like “common mode failures,” where members of the security council might all experience the same kind of attack, such as collusion or hacking.

Note that these assumptions are very imperfect. In reality, security council members have "common mode failures": they could collude, or all get coerced or hacked the same way, etc. This makes stage 0 and stage 1 both less secure than they appear in this model, and so moving to stage 2 is optimal somewhat earlier than the model implies.