Yes, like I said, you pre-cast invis while the chest is coming up. There's like 12 dig sounds (don't quote me on the number) as long as you pre-cast invis and have yourself targetted, you can release the spell when the MOBS spawn.
You will be invis and since they weren't aggro'd to you, they won't reveal you. Instead they attack the 2 Earth Elementals you summoned and put a few steps to the side. When at least 1-2 target the EE's you run the opposite way.
Deal with the spawn however the char is setup to. I use Provoke and EV's myself. Then come back in and get the chest fired up. If something spawns while dragging out items, it won't attack the second it shows up. You have time for a spell... invis, pre-cast heal, etc...