It would seem that you're grounded until you replace the part. I'd call or email Dahon for a replacement part, and once I had it in my hand commence to removing the bent one. Removal may call for a hacksaw, or cut off grinder. Cut the bolt above the nut, clean up the cut, and work it out forward so you don't jam it trying to back the bent area out.

BTW- while your ordering the part, also order the part it threads into, as you might damage the threads while trying to get the bent bolt back out.