Note that with the GPU hardware most miners use, scanning the whole 2^32 range of nonce values takes a matter of seconds. Mining software will scan the whole range looking for a valid hash for the block and then increment the timestamp or reorder some transactions so it can try again.
Why would the miner increment the timestamp or reorder to try again? Once they get a valid hash for a block, wouldn't they just want to simply claim the 50 coins and move on?
The miner will scan the whole range looking for
a valid hash. Only one time in ~1.6 million this scan will result in finding
a valid hash. If it doesn't, the miner will tweak the header, typically by increasing the timestamp or the extraNonce.