Why does blockchain.info show the warning "Transaction rejected by our node. Reason: The transaction is not final"?
BTCJerk on reddit noticed that "Blockchain.info is having issues, the last block they show is 442341". Other block explorers were already on block 442349…

Since the transaction was timelocked until block 442345, and timelocked transactions are considered invalid until the appropriate blockchain height is reached, blockchain.info was still considering the transaction invalid due to its lagging behind.