Chat message sent while AskUserQuestion is open reports to the model as a user dismissal

What happens

An AskUserQuestion is presented. The user types an unrelated chat message and presses enter. The ask closes, and the model receives:

[User dismissed - do not proceed, wait for next instruction]

Why it matters

That string is indistinguishable from a deliberate refusal, so the model treats a decision as made when the user never made one.

In my session the assistant reported an item as "parked on your word" and stopped work on it. It was parked on a keystroke aimed at something else entirely. The user only found out because they happened to contradict it a few turns later.

The failure is silent in the direction that hides it: nothing in the transcript distinguishes an ask that was superseded from one that was answered no. Neither side has any signal that a decision was manufactured.

Expected

Either the ask survives the chat message and stays open, or the model receives a signal that separates the two states, for example:

[Ask superseded by a new user message - still unanswered]

Anything that distinguishes the user said no from the user said something else.

Reproduction

1. Have the assistant present an AskUserQuestion with two or more options.
2. Before answering, type any chat message.
3. Press enter.
4. The ask closes and the model reports a dismissal.

Environment

Claude Code desktop, Windows 11, Opus 5.