What? Gravity on Dilbert's tie? Man, better tell Adams that every single other comic (except that one where we suspected he finally got lucky) is drawn with gravity wrong. Man...gravity pointing down...what a crazy idea.
apharmd, do you know about gravity? If you do, then you should know that since gravity pulls things down, that means that Dilbert's tie would be pointing towards the pit he is suspended over, and not towards his legs. In other words, Scott Adams drew this situation correctly.
Here's one of the easiest ways to prove that in reality. Do a handstand and have someone else tell you what direction your hair (or a necklace or tie or something) points. If they're being honest, they will tell you that your hair (or whatever you decided to test) is pointing towards the ground, not towards your legs.
If you can't do a handstand, then have someone else do it for you while you watch.