Every time I've tried to use DuckDB it has segfaulted on me, so yeah I'm betting on DataFusion..
That is very surprising to hear! If you can reproduce it, could you please file a bug report on GitHub? That would be a huge help!!
I personally filed bunch of bugs, they mostly were autoclosed because of no activity after 3 months. This is very discouraging, and I rather invest effort in looking for workarounds in the future.