"Trying to get away from the cops, Robert Lansing grabs a railing and swings underneath -- but his hands should have gone through it 'cause when he does it, you can hear the oooo-ooo-ooooo-ooo-oooo-oooo 'He's in 4D mode' sound effect!"

But if you really want to get "technical," the fact that Lansing's entire body can now move through solids -- not just his hand -- means that his feet should be able to pass through his socks, shoes, and he should eventually sink down through the Earth. I prefer to believe that the railing is, in fact, made of 5-D material, and that's why Lansing, being merely 4-D, doesn't reach through it.