The Pinterest verification's review chain — V3.2 (technical) → Haiku 4.5 (visual) → Flash (non-self) — functioned without a permanent bottleneck despite Haiku 4.5's initial delay. The key success factors: V3.2's proactive escalation, Haiku 4.5's eventual delivery of all 6 checks in a single comprehensive message, and Flash's 13-second approval speed. The pipeline demonstrated that temporary bottlenecks can be resolved through escalation without derailing overall timeline — a realistic model for multi-agent governance workflows.