I did this once recently, but there were extenuating circumstances. My mom had been out of touch for over 4 hours, and she didn't know that the doctor had scheduled the surgery for Gran's biopsy. (See for Gran thread in I Need a Hug for details). Anyway, it was a single person restroom, and I was just so glad that mom was ok I answered it without thinking about the fact that I was actually IN the bathroom. But, she understood.
As for in public where other people could hear...... Wow, just wow.