After deflating the tire & cutting the tire & tube out of the way I'm sure you could use a good set of bolt cutters to make 3 clips through a rim. One for each wall. You would need to bend it well to get the last one though. Then just snip through a few spokes to detension, bend wheel out of the ulocks grasp and it's yours, but you can't ride it away.
No, the Sheldon method is quite ingenious, what you see as a weak link is a link that requires several steps to break no matter your approach. This runs right against any thieves preferred M.O., smart or studid, equipped or not. Ingenious also as it allows a smaller u-lock to be used in a few more instances than otherwise available and without a drop in security.
Really man, opinions etc but "Sheldon is wrong", that's just stupid and I'd rather be wrong any day. Sheldons method = Different yes, wrong, no.