Bit of a difference between throwing matches on diesel and having a red hot piece of metal getting oil poured onto it, especially when the metal is getting kept hot by the friction.
Granted in the afore mentioned case the tip had broken so it was steel to steel but that can easily happen and usually happens when you turn your back for a few seconds
I had a U Drill that welded itself to some stainless in a fraction of a second when a tip broke and I was actually watching it at the time, first I knew was when I saw the red glow through the white water and by the time I hit the E-Stop it was well knackered, if that had been neat oil I would not have been reaching for the E-Stop but likely calling the fire brigade
Just be careful and dont get complacent.
Hood