The Goblin Pub was located in the basement, specifically, three floors below the ground floor of the castle. There were two ways out from the Goblin Pub. However, one of these would lead to the outer gardens which were nowhere near the Reception Halls nor the Throne Hall, unless one had a gadget that allowed them to fly and sneak in through there.
And that was exactly what Ripcaller was suggesting until he realised something important. "Wait…if the magic portal was up just minutes ago and wasn't affected by the Leyline magic…then how did Master enter so nonchalantly with us? Does it mean his portal magic was able to intervene against the magic barrier?" They all looked at Jin with the exception of Starfire who thought that the person in the half Panda Mask was a nobody.
