I think I have a case of the Mondays regarding rules... this came up in the other forum and I believe the enforcement concepts are the same, and I'm not following how they arrived at the enforcement.
'The fun caseplay on this is when R muffs the kick beyond the LOS, K recovers behind the LOS, then K throws an incomplete pass. Result? 1st and 10 for K. Fun!'
So, let's formalize this:
4/10 from A25. K22 punts the ball, where it is partially blocked by B50, and bounces beyond the NZ to the A30. In his attempt to secure the ball, B88 muffs the ball (at the A30), causing it to go back behind the LOS, where A13 recovers the loose ball at the A20. He then throws a forward pass, which falls incomplete.  Ruling? 
B's muff of the kick, beyond the NZ, opens the door for either team to gain possession. The kick ends when A13 recovers the loose ball, and A got the ball with clean hands, and a new play segment begins (a run). It would be A's ball, 1/10 (since continuity of downs was broken), from the... previous spot? 
When a foul is thrown in, such as IDP?  Why wouldn't the correct answer to mark off the penalty from A's possession point, and go A 1/10 from the A20, since A recovered the kick fair and square (clean hands)?