gearlever Indeed, my bad.
FCOM DSC-31-15 "D" INDICATIONS ON E/WD - Flight Phases
(could someone please dig the time limit, or am I imagining things...)
Similar to your remark, I am afraid that if you really had a burning spray of leaking hydraulic fluid, the BRK temp sensors wouldn't pick it in time due to airstream cooling. Bang, the doors close.
But there is a reason we do not have a fire DET loop in the bay, so trust in the engineers need to keep you safe.