This corresponds well with timestamp of last transactions for 18k address, so this seems to be Bitstamp cold storage.
no it doesnt. 2 more transactions after that.
It takes 6 blocks to confirm.
After 9:00 UTC, these are:
337587 16b31eefe6... 2015-01-05 10:11:44 6
337586 16ff08b25a... 2015-01-05 10:04:46 5
337585 16465ee71b... 2015-01-05 09:52:23 4
337584 12006e66ec... 2015-01-05 09:46:56 3
337583 7730199b94... 2015-01-05 09:27:59 2
337582 ac693e4185... 2015-01-05 09:18:58 1
337581 6b1fd11dad... 2015-01-05 09:00:15
So transactions sent in block 337581 (up to 9:00:15) could only have been received by 10:11:44