If you get into a situation where there are clear sides and you and your company are obviously on one of the sides you can beg the argument. Just say that there are different points of view and that you aren't there to debate the issue. Nobody can make you debate if you don't want to. Sometimes things get so heated that you might be heckled and hassled from audience members. Just ignore them. By being persecuted and taking it quietly, you will gain sympathy from other audience members. A sympathetic audience makes a good audience. If you argue and get into a debate, your audience will get defensive. That's not so good.