First, no one "forgot to turn off the cutting torch" Use one for yourself, and you'll see the cutting flame has to greatly heat up the steel before it will cut. Finally, during the cutting procees, after the steel is heated properly, then the oxygen pedal of the torch is pressed, introducing proper oxygen content to the cutting flame. You can't leave marks like that on steel rail just by dragging a lit cutting torch across it.

You CAN, however leave gouges like that if you decide to use the rail like a sawhorse and cut up something laying on top of it. The cutting flame will mark the rail like that as it passes through the material being cut, should the materials be laid right on top or close to the top of the rail in question.

Those marks were probably the result of the salvage contractor during the dismantling phase.

My brother has a nice porceline warning sign like that pictured, except on the bottom of the sign it says "Santa Fe System".