I note that the National Lottery responded by attempting (with partial success) to block the guy from his victory, and also making such things unfeasible in the future.

As a general rule, when you game the system, the system changes to stop the game, because the organisers have a goal beyond the rules of the day. So there's only a certain window of opportunity to profit. If there are high stakes, you need to be really sure that there is a gap to work with, in between "no-one has done this before, so maybe it doesn't work for reasons I haven't seen" and "everyone's doing it, so does it still work?"