> Neither Rust nor Python enforce high-level data structure integrity (e.g. transactionally pulling data off one queue and stuffing in another).

Rust absolutely does. For instance, if you unwind while holding a lock, the lock gets poisoned, preventing further access to the locked data. If you're not holding the lock, no safe Rust code can possibly corrupt it, unwinding or no unwinding. So you definitely can put a lock around your two queues, operate them from multiple threads running safe (or correct unsafe) code, and be robust to a panic in one of those threads.

I'm less familiar with Python's concurrent structures, but as I keep saying, this is why you leave the stuff that touches the data structure outside of your try/except - Python does guarantee that a thread that doesn't have explicit access to a shared object can't mess with the shared object by mistake.