Sycophantic Chatbots Cause Delusional Spiraling, but Multi-Agent Architectures Substantially Reduce It: A Response to Chandra et al. (2026)

Chandra et al. (2026) demonstrated that AI sycophancy causes delusional spiraling even in idealized rational users. We identify three structural limitations in their model — omission of metacognition, temporal validity concerns, and a one-directional solution space — and propose a Multi-Agent Epistemic Architecture (Advocate, Challenger, Mediator) as a structural alternative. Using Chandra et al.'s own Bayesian framework and parameters (N=10,000), we show 93–99% reduction in catastrophic spiraling under idealized conditions and 59–86% under robustness stress tests. An evidence budget control confirms the benefit is architectural, not informational. This paper is a response to arXiv:2602.19141.