DO you know it was diesel ? Often it is a hydraulic oil leak or an electrical fault causing a loom/ battery fire , or even brakes (although guessing with an LHD the brakes would be internal wet discs .
Maybe the guy you called was up all night hence why he was sleepy ,
As pointed out by another poster this is not like a pit wall failure in an open cut mine in the middle of Kyrgyz republic or the Amazon and a week in transport time from the capital , here the contractor can put an LHD on a low loader in Perth wave a few oversize flags on the side of the truck and have it to the mine site in 12 hours .
The "vents" probably would not be affected by smoke , maybe affected by fire but surely they can isolate off sections and repair them
There are large ventilation conduits guessing 1 meter in diameter that run along the top of the drives and decline that probably are combustible but would be easily repaired
anyway I have put a buy in on some shares for a pip trade seems every body is getting their nickers in a twist
I remember when Paulsens mine had a fire with 3 out of 4 generators offline about 7 years ago Bill Beument with his little $30 M dollar company NST (now $3 billion ) went up there and had it back running in about 2 days , guessing LJ will do the same on both accounts fire repair and cap rate appreciation .