IL thanks,
In the first instance where the Captain decides and acts, it is assumed that s/he has recognised the situation. If not, then the P2's alert (as a handling PM !) starts the Capts time consuming assessment, decision, and action.
Re 'stop'; yes I assumed a decision.
An alert as above is more relevant, but the opportunity for dissidence remains - thoughts opposed to actions, although the latter is a risk with over emphasised assertive training - CRM.