Have you sent a fee with it?
If not, you probably have to wait a few more hours.
Yes, he did, as you can see in the link he posted
1 - transaction details, including fee used (0.0001 BTC), are shown.
Could it be the case that there are other unconfirmed transactions still pending (which the funds you used here depend on)?
1 -
https://blockchain.info/tx-index/4b19a80b97bafacd02b67a781b146a832c319328212ec80f18be26252a66725dEDIT: looking at the input addresses, that doesn't seem to be the case either.
EDIT2: yes, definitely not the case; I just noticed blockchain.info adds a warning after "Estimated Confirmation Time", clearly stating it if a transaction spends an input which is unconfirmed.