Garden Pests and Diseases: Correct diagnosis?, 1 by fpk473

fpk473 wrote:
I planted two Sedum Autumn Fire this summer. Attached is a photo of one of the leaves. This is appearing on both plants. I took it to a garden center this morning and was told it is from water sitting on the leaves and then the sun scorches the leaves. Although the plants have a southern exposure, they are close to the house under a partial overhang so they get sun later in the day and that isn't even full on harsh. Does this diagnosis look/sound right to you?

Thanks!