Why the difference?

Team Racing Calls H5 and E12 appear to have different interpretations.

H5 says that when a boat rounds a mark wide her proper course may cease to be close to the mark before she has left the mark on the required side. In such a case 18.2(b) still applies but the mark room to which she is entitled no longer includes room to sail to the mark. 

E12 says that when a boat "sails beyond where she needed room to round the mark as necessary to sail the course, the outside boat is no longer required to give room"

E12 is dealing with room to tack, and the diagram in H5 has the outside boat abeam of the mark at all times. 

The question is should the decision be the same, if in H5, the boat had continued downwind, such that she was no longer abeam of the mark, but past it in a downwind direction? ie a line abeam from her transom was clearly past the mark? Does 18.2(b) switch back on when she turns towards the next mark? or is 18.2 off and she has to stay clear of boats that have right of way?