I've got a digger too, but she isn't the one who steps in her poop. She digs and buries and digs and buries scratching the sides of the litter box if she's in the high sided one, reaching over the scratch in the other boxes if she's in a low sided one, until she has a nice tall pile of litter. The problem is, the pile of litter is no where near the poop.
I've watched my poop stepper. She poops standing on the sides of the boxes. The boxes are plenty large enough and always clean, but she does this anyway. (in her early days she did not have a clean litter box, and I suspect that is where this habit came from)
When she's done, she drops down and turns to inspect her work, stepping in it with her hind foot as she turns. Then she buries, likely as not stepping in it again.
I can usually tell which cat pooped what, and hers is the easiest of all because there is always one flat section.