Disappearing Credit Card Transactions After Over Limit

Just came back from a travel from overseas and as usual it racked up a good pile of pending transactions on my credit card, which may take days to settle because they are international (obviously I used a card that does not charge international transaction fees).

I am a bit pushed up to the limit on my CC at the end of travel - but all the transactions went through at the vendors without an issue. The usual way it works is on every purchase I make, my available credit on the card is reduced (instantly) by an amount that is slight more than the amount in AUD calculated with the exchange rate on that day, leaving a small reserve for if the rate moves around. No Problems.

But the curious thing happens as the local currency where I traveled (JPY) went up like crazy last week. The result is that I ended up having over a hundred dollars than excepted on my statement as some of the transactions are settled with the elevated exchange rate, which immediately pushed my card over the limit with a few transactions still pending (before that I　also used the card several times in Australia which got quickly settled and pushed the limit even further).

I went on to make some payments on the card to close up the immediately due amounts, but because that's on weekend, it took several days to go through. By the time the payment is acknowledged by the CC company and my card is off the limit again, those pending transactions on my card just magically disappeared (just like those card authorizations that never got charged when you book a hotel).

I know it's not much of my worry because I eventually I just need to pay whatever is on the CC statement. But I am just curious about the mechanics of the chain of event here. Where did these transactions go? Will they ever come back at me at some later time and if the answer is yes, will I be charged extra? More curiously, if I　were the vendor involved in such transactions, will I be screwed?