That damage seems very odd - must have taken a lot of force to distort the rim so much, yet there are no obvious impact / abrasion marks in the area of damage while the tyre appears fine and evidently remained inflated.
Was there anything on the inside / bead seat of the rim that might give us a clue as to what happened?
Also, beware ally work-hardening. IME you can often bend stuff back to close to where it started, however this will weaken it and the closer you get to the starting point the more brittle it will become. I had this with the bars on my Routier - the closer to "correct" they got the more the load required to bend them seemed to ramp up exponentially... I suspect if I'd pushed them all the way they'd probably have snapped or perhaps started bending elsewhere.
Was there anything on the inside / bead seat of the rim that might give us a clue as to what happened?
Also, beware ally work-hardening. IME you can often bend stuff back to close to where it started, however this will weaken it and the closer you get to the starting point the more brittle it will become. I had this with the bars on my Routier - the closer to "correct" they got the more the load required to bend them seemed to ramp up exponentially... I suspect if I'd pushed them all the way they'd probably have snapped or perhaps started bending elsewhere.