Could you have a purpose built browser that receives the packets up to
<?xml version='1.0' encoding='UTF-8' ?>
<outcome prizeTier="14" amount="0
and buffers them all, possibly while returning a fail code, and then only returns the acknowledgements that the packets are received if that last figure is positive?
Presumably they handle this sort of thing, curious how they do it? Is it simply that if they can't send the page you still have to pay - could they then be successfully sued if your connection is down or theirs doesn't actually deliver the packets but you're still charged?
This last scenario would appear to fit into the sale of goods act in that you've paid for a service (a scratchcard game) but the game wasn't delivered ...
Clearly if I was a black-hatter I'd just try it out ...