I found this concerning:
There was one camera installed on the leading edge of the right
horizontal stabiliser. This camera could provide the flight crew with a
vantage view of the fire.
According to the flight crew, they would usually switch on this camera
system when they are taxiing the aircraft, as required by the operating
procedures. However, in this occurrence, they did not switch on the
system because they had not reached the taxiing phase as they had
been instructed by ATC to stop at the intersection between the runway
and rapid exit taxiway E7
Other than that, and points already mentioned, I think the "sniff test" is a cop-out, and that the MFOHE checks and replacements should be completed by "yesterday".