Skiing a 13er in January?

The only sign of instability occurred when Maggi took a tumble and I skied up to check on her when we were just entering treeline. She was OK, and when she made about 3 turns away from me, the slope I was standing on made an ominous "whoompf" as the snow settled. Maggi called back to tell me she just saw it crack, but I was already straight-lining to safer terrain. The slope did not slide, but instead just gave us a verbal reminder that it was January 2nd in the San Juans.