I don't think that example is actually a good one. Exchanges need at least 2 people in order to do trades, whereas this particular case we've been discussing (which now brings up the question of whether this should be continued in gambling discussion) only involves one person.

I may be wrong about this, but I still see making a double spending and not doing a deposit as the exact same thing. Does it affect the overall casino economy? Well, that's for sure; but not the point here...