LOL.
The company I used to work for (plants and gardening) had a segment on QVC several times this past year, and I can tell you she shows are live and the callers are real! She was most assuredly watching while calling, since they often show something on-screen and discuss it with the caller. The studio setup is amazing though... they track how many more phone calls they get after each buzzword, then alter the script "on the fly" to react to it. Crazy. And fascinating. And more than a little scary how much science goes into it.
ALL THE FUNNIER that the guy falls off the ladder on live broadcast. "He's moving...he's ok!"