I am an official and made a call over this last weekend that I wanted to verify was correct. A majority of the group agreed with me, but there was one dissenter - so I thought I would double check with the DG community.

Situation:
Player had a tough shot underneath a bush. After marking his lie with a mini, he put his left foot 11" behind the marker (within the 30 cm) and his right knee in line horizontally with the mini.

His argument:
Dissenting player claimed that it was a stance violation. He argued that the supporting point that is the 30 cm behind the marker must be the forward most point. By having the right knee in front of the left toe, this was a stance violation.

Our argument:
Based on these two phrases in the rule:

1) Have at least one supporting point that is in contact with the playing surface on the line
of play and within 30 centimeters directly behind the marker disc.

2) have no supporting point contact with the marker disc or any object closer to the hole
than the rear edge of the marker disc.

We claimed that we satisfied both of these conditions and therefore was a legal stance. Were we correct in our ruling?

Yes, that is correct. The supporting point behind the marker does not have to be the point closest to the target. Often when a right handed player has to put their left foot behind the marker they will put it at the back of the 30 cm so they can place the right foot slightly forward of the left and still have both behind the rear edge of the marker.