Another_CFI
Speedbird252 also had Whitchurch - Hook VRP - Guildford planned (and no, I'm not his instructor

) and was expecting to use that routing if told that Odiham was busy. Having told Farnborough Radar that his route would take him through the Odiham ATZ, the subsequent clearance to enter the MATZ didn't say that he couldn't use his intended route - and it's easy to think of that as an implicit clearance through the ATZ.
Umtali has explained the issues here - and thanks, it has cleared it up for me too...
I did the very same navex during my training, and Farnborough directed me around Odiham because it was busy. That was midweek. However, I have always assumed that Farnborough 'owned' the Odiham ATZ, and (now as a PPL) I would have done the same thing that Speedbird252 did - so I guess you can be amazed at me