Dude, they're saying when IT RUNS OUT. No seconds left, no minutes, no hours, no days.
WHEN THE TIME IS OUT. When the LAST person LOSES his coins, the HOUSE get's it. Who else would get it you say?
Jesus Christ on a bike. This is like teaching a turkey Chinese. Ill try and explain it and see if once people get it, Im offered an apology from anyone..

Price opens at 1000 coins. Interest is set at 50%.
So - player A is the first to buy he sends over 1000 coins. He holds the bomb and waits for his 50% interest.
The price is now 1,500 coins.
Player B buys the bomb. he sends over 1,500 coins.
The house takes 1% (15 coins).
The remaining 1,485 coins are sent to Player A so he gets his 50% interest.
Now the counter reaches zero... there are no coins there waiting to be kept by the house. The house had 15 coins interest, the other 1485 were paid out. All that hapens is the counter gets reset and the person holding the bomb when it got to zero just never got anyone else to pay their interest. Thats it.
Im honestly havig difficulty trying to make this any simpler without drawing a picture.