Removing an embedded stone?

[Beezerk]

Had a bit of a situation in a pairs matchplay comp on Saturday, our opponents hit a wild drive and found it half plugged in the rough. It was a really bad lie and after some discussion he decided to play it as it was, he then said "oh there's a stone there in front of my ball, it's going to damage my club" he duly dug the stone out which was the size of a large egg, threw it away and took his shot.
My PP and I were a bit bemused, we didn't really have a clear view of what he was doing but the stone was certainly not "above ground" as such.
We somehow won the match so it didn't matter in the end but did we have grounds to pull them on it?
Loss of hole maybe for improving his lie or summat?

 

[Colin L]

A stone is a loose impediment unless it is "solidly embedded". Judging by his having to dig this one out, it seems it was indeed solidly embedded and he should not have removed it. He was in in breach of Rule 13-2 by improving the area of his intended swing. The penalty is loss of hole in match play and 2 strokes in stroke play.

He could either play the ball as it lay with the stone in place or deem his ball unplayable.

 

[Hosel Fade]

"Loose" impediments have to be loose, loss of hole for improving area of intended swing

 

[Beezerk]

Thought as much, thanks a lot.