Given 1 BTC sent to two different addresses, there is maximum only one of them that is valid at one point in time. However after some time, the other coin coul

Given 1 BTC sent to two different addresses, there is maximum only one of them that is valid at one point in time. However after some time, the other coin could be valid and the first coin could be invalid. The timing attack gets harder the longer time has gone since the coin was sent.