>>1380361Theory time: cranksets tend to flex, or just generally it's the bottom bracket area that does.
Is it possible that as you or the mong that sold it to you as were pushing the crankset, you ended up rubbing that buttplug thing into the frame? That cut is definitely the result of something digging into the frame for a long, long time, and unsurprisingly, you put the most pressure at the bottom of the crank, which would indeed push the crank inwards.
Could it be?
