For example, I just gambled 1.6 on 50% but it got double spended.
And thus it has become an invalid bet. SatoshiDICE only guarantees the payouts it makes will confirm if your wager confirms as well. So your bet to them ended up being invalid.
I won and got 3.2 btc back, but that transactions is also double spended.
Yup, that will never confirm if it ended up being a double spend.
