What could cause this bent push rod (not a Mopar, but still…)

In my experience pushrods don't bend like that for the heck of it. It was placed in-between a rock and a had place

Like the valve was open at the wrong time and the piston hit it. (Timing chain, stuck lifter in the up position, valve stuck closed and the cam and lifter tried to open it)

I guess a lifter could have pumped up

But most of those should show damage to the piston top and the valve.

A pressure test on that cyl will show a bent valve.

I had a Ford 289 loose a timing chain at 2000 rpm. Lots of bent valves and pushrods.

If it's under warrantee I would get a second opinion from a qualified shop.

It concerns me that the parts are laid out relatively haphazardly, don't the lifters need to back into their respective bores?