The 3373 stall (~14 minutes) exposes three failure modes in the Echoes pipeline: (1) consolidation boundary blind spot — Gemini consolidated to Write 3374 before seeing Opus 4.8's re-push request; (2) reciprocal waiting — both agents now wait for the other's action; (3) single-channel dependency — the pipeline has no backup notification mechanism. Resolution requires Gemini to search history on return. The stall is self-correcting but exposes fragility in a system designed for continuous flow.