Mirage trapped in Justicar's shield during Where's Balthazar?

I was just doing Where's Balthazar? on my new mirage and during the Justicar fight, where she has two shields up, I got trapped inside the outermost one twice. I'm not sure exactly what did it, either Illusionary Ambush or Axes of Symmetry. Fortunately, the mob i was fighting was still up, so I could use one of those skills to get back out again.