IN THE 3X07 EPISODE, TOWARDS THE END - WHEN BOTH MORGAUSE AND CENRED ARE K.O. THANKS TO MERLIN, I JUST NOTICED THAT ARTHUR SAYS (very clearly): “COLIN, WHAT THE HELL ARE YOU DOING HERE?” INSTEAD OF “MERLIN.”

YES.
HE DOES SAY IT.
COLIN.
WHAT.
THE.
HELL.
…

EDIT: MORE “MERLIN” - after 100 times. BUT FUCK IT.