Odd yeah.
To me the spotting looks like nutes, but the big cruncy part looks like a light burn to me.
I say lights because it looks like its happen to only 2 leaves mainly? both next to eachother. One at the base on the right side the other the whole leaf except the base. Unless I am seeing the picture wrong it looks like it had a nice hot spot right where those 2 leaves are. Someone else may be able to shed more light, or maybe you can post a few more pics more up close?