Hey Glenn,
It is possible to group chain saw piston failures into some "typical" descriptions regarding reading the failures. There is always the odd saw that doesn't fit the typical failure, and some saws may have multiple faults that may cause a-typical damage. Having said that, I feel you have a typical lean running failure, which in my experience is the most common cause of damage in a chain saw. Be sure to check for any faults present before running it. It is best to do a vac/pressure test before teardown to see if the engine pan or seals were leaking. Was the H screw in too far? Impulse hose in place or leaking. Fuel filter restricted or a hole in the fuel line, tank vent working properly? I always do a full analysis of the unit before teardown to locate any and all faults present, and then those faults should confirm why the engine failed and match the damage.
Typical lean damage is scored exhaust side with little or no damage on the intake side, blue wrist pin and needles, and there may be some scuffing on the bottom of the intake side due to high RPM piston slap.
Typical unmixed fuel is damage on both sides of the piston, do a blotter test to check the fuel in the carb for oil. When you check the engine before teardown, you probably will not find any lean faults, which helps to confirm that it was lack of lubrication.
Overhear failures will usually show 3 or 4 corner scoring on the piston, and some melted plastic around the cylinder, and again, no other faults will be present.
Check the threads last week or two about using acid and fine emery to save the cylinder, and you may be able to just replace the piston.
HTH
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