Yes. That's a great temporary purpose for a Refugium.
It's also likely that the Tilefish was just not doing well anyway. An Anthia would be prone to picking on a fish that is unhealthy and just taking up space in it's territory. Now that it's almost gone, I'll bet the Anthia is ignoring it, right?
Tilefish are slow eaters, while Athias are extremely fast eaters. Depending on which Tilefish this is, it may have starved because it wasn't fast enough to get enough food.
I'll text or call right now.
Aloha