There appears to be inconsistency within the adjudicators - in this case the adjudicator invited the appellant to tell him that the boards were pre-ordered, and that was seemingly the deciding factor, whereas in the case that gave rise to this thread, pre-ordering was deemed not to make any difference.
The law has generally preferred certainty to the more nebulous concept of justice.
If the loading exemption applies to collecting (and paying for) pre-ordered items that could not easily be carried a significant distance that is a reasonably well defined pigeon-hole. I do not know the nature of the boards in question, but 4 boards sounds like something that you wouldn't want to drag half way across town. A watermelon, less so IMHO.
Where there is a reasonably well defined exemption, there will generally be ways to game the system to stretch the exemption - this is box ticking as opposed to weighing up the merits. If you can tick the relevant box you win, regardless of whether another case with no less merit would lose.
However, you seem to be suggesting that one could "legitimately" game the system for using the parking exemption to park up while making a phone call to pre-order the item. If pre-ordered is a relevant box to tick, using the loading exemption to collect and pay for the item would seem to qualify, but I would suggest that making the phone call would not - you cannot use the loading exemption for making the phone call.
