Shepard is not an expert in robotics, in particular not the kind that Garrus is holding, a clockwork thing of copper wire and weird bulbs, but she knows a few things. Practical experience tells her that when a small, otherwise innocuous, device starts making those kinds of noises, and that much smoke, there's really only one outcome.

"Throw it!" she barks, all command. It's going to explode, and while it might not do much damage, Shepard isn't confident enough in that assessment to want to risk subjecting Garrus to the local medics, "It's gonna blow!"

And so it goes. Was there ever a mission that didn't blow up in their faces, one way or another?