Certain drills / circumstances state an Evacuation is required. Clearly as Capt you can decide not to, but that is a brave decision
One of my/our criteria is a "
Confirmed and
Unextinquished Fire" i.e. I will not evacuate for a fire warning that does not go out, but there is no confirmation. Ditto, a fire seen by the tower on an RTO, but my colleague states after firing the bottles the fire light has gone out, I will also hold off.
Do NB it is not an "Evacuate" or "Not Evacuate" decision. There is a middle road of "Not just yet". Whilst the doors are armed, you can be 3s from initiating an evacuation until you disarm them and stand everybody down.