It is written poorly, I agree.
Yeah, It's clear they don't entertain double spending, however the explanation about the double spending practices is completely off. Maybe Steve and the sportsbet.io team can pick off from here and try to improve on that clause to avoid future disputes.
Once or twice I couldn't withdraw and then I have seen it did not confirm yet and had no problems withdrawing after that confirmation passed.
Exactly that's what I observed with platforms where accounts even on Zero confirmations, you can't withdraw minus a blockchain confirmation at least, but that TOS clause paints a different picture.