You're talking about the core/userland boundary beyond the origin tick, and we're both right. Promises coerce caught exceptions occurring on the origin tick to errors (bad), while allowing non-caught async errors to be handled in a custom manner as you point out.

The comments following your linked comment address this nuance. I agree with Raynos that the core of the issue is as I point out here, 2 divergent incompatible error handling mechanisms, with both of them fundamentally broken:

* error passing fails because we don't have CPS due to lack of Proper Tail Calls

* throwing fails because we lack async try/catch or at least with async generators we lack a performant try/catch or with bluebird-like optimizations (hacks) we lack typed catch and Error.create

The latter is far closer to a consistent error handling pattern than the former, which promises implement (poorly and verbosely IMO). Additionally, async generators also nicely address the issue of slicing your userland stack away from core, so you get a two for one.