In this segment of Mock the Week, the topic was "Unlikely lines from a cosmetics commercial". She said "We don't test any of our products on animals. We use Filipino children." I doubt people will react the way they did if she said Indian or Chinese or African children.
If you watch Mock the Week, you know the format of the show and should never take anything of it seriously. If you are someone who gets offended at the slightest comment like "you're ugly", "you're fat", etc. then don't watch this show and the likes of it because you'll definitely get worse comments than those. It's like Little Britain but with 6 stand up comedians outdoing each other with their comical statements in front of a live audience.