Looks like the threaded end of the bolt is bent. The bolts are still available from Honda. I would rotate the bolt to verify whether it's bent or not (watch the threaded end of the bolt for eccentric movement). The "collar" portion is not much bigger than the bolt, so even slightly bent would be difficult to remove. If it is bent, you might be able to hacksaw the threaded end off, or remove the fender, hacksaw the head of the bolt off and remove the bolt from the inside.