I'd guess that since the bolt broke, it had previously worked loose and the "fix" was to force it instead of finding the loose bolt & tightening it. Since it was loose, the entire assembly moved in ways it wasn't supposed to and that's what lead to metal bending and enough force in the wrong direction to break the bolt.
I would suggest that your best bet is to replace all the bent/broken bits with properly fitting parts and that with straight pieces of metal (where they're supposed to be straight, of course) and properly tightened nuts/bolts, you'll have solved all the difficulties.
The odds of bending those arms straight and having them stay straight are pretty small. You'd probably be better off simply replacing them.
You could call the manufacturer and purchase replacement parts, but it looks like simple, straight aluminum bar stock and you might be able to pick up proper sized pieces at your local big-box store or metal supplier. Aluminum is easy to work and you can cut to length, drill the proper holes, and round over the edges to make them match.
As you reassemble, you can reuse the bolt that the handyman installed, then cut it off after installation so that it doesn't rub on anything (also, make sure that it's not so tight that it's preventing the metal from pivoting freely). Or, you can purchase a shorter version of the same bolt (ensure that you've got the right diameter and thread pitch by bringing the nut & bolt with you to the store and get a new bolt that will easily thread into the nut, but is shorter than the current bolt).
I would suggest that proper maintenance (immediately look for loose bolts and tighten them if/when you notice it starting to be difficult to open/close) will prevent these issues in the future. To help prevent the bolts from loosening, you could use lock nuts (NyLock™ or similar) or lock washers, but do remember that you can't tighten them down so much that it won't allow for movement. Proper maintenance is probably the better way to go, especially if there weren't locking nuts/washers on there in the first place.
Final note: If your handyman tightened the bolt so much that it's preventing easy movement and/or left it so long that it's rubbing on the metal ladder and preventing easy movement, it's probably time to find a new handyman. I wouldn't want the same guy doing more shoddy work in my house if it were me...