Maybe it is a bug that recent came in the game, but I can remember numerous times when I hearthstoned on my alt from kara to repair (not enough rep to repair at blacksmith behind first boss), and on the aldor terras (where my inn is) I went to the house at the opposite side to repair... When you repair, its talking to an npc right? and the time just kept counting.
If i do remember correctly, they DID change something about npc's, like for example if you click a flightmaster these days you don't need to click a second time on a line like "show me where you want to go" but from 2.3 he immediately shows the flightpad. Maybe due to that change this bug is working... Can't test from here, at work atm