People fall into one of three different learning styles: visual, auditory or kinesthetic. Andy is clearly kinesthetic - touching is just the way he commuicates and learns about people. Many women are auditory - many men are visual, which is what leads to all of those stereotypical "Why don't you listen?/Why don't you see?" arguments.
An auditory or visual person who doesn't understand kinesthetic people will often look at an example like Andy touching Bevin's knee and read into it all kinds of ulterior motives, because they would choose to communicate differently in that situation. That was his way of saying "I'm sorry, Bev," but many auditory fans watching at home are screaming at the TV: "Why doesn't he
say he's sorry instead of groping her???" It's hard to explain to them that he
is doing just that.