Illegal Touching+4th Down+IW=???

[buckrog64]

4th down. A throws ball which is caught behind the line of scrimmage by ineligible A. Flags fly, an inadvertent whistle sounds and the ball is blown dead behind the line to gain. If I read it correctly, I think 4.2D applies here. I wasn't at the game but I think the ball was given to B at the spot of the foul for a 1/10 for B. Not sure that was quite the right thing to do. Should the aspect of the IW be ignored and march off the penalty plus LOD? Thanks for your input.