Ive always been curious but honestly never looked but can you bet on free kicks and at certain times like you can bet on no balls etc in cricket. If so this is probably the bigger issue because this is how betting issues evolved in cricket and became a huge issue and probably still is.What will make a difference will be the betting agencies getting up in arms about the potential for matches to be fixed and umpiring to never be considered as a possible source. We turn a major blind eye to umpiring howlers that don't even out in games. Last Friday was as close as I have seen umpiring being hard to explain away in any other way and the difference in interpreting rules by the same umpire in the same game, particularly the oob decisions were enough to raise an eyebrow at the very least.
Wait for fr the bookies to be absolutely burnt and then you might get somewhere.