Tom,
I first noticed this last year when I visited a golden age course after a restoration. There was a green over a bunker that sloped away, with native beyond. I wasn't playing but my guide was a member and he showed me the issue and we tossed a few balls and they ended up dead against the low side. The bunker has since been rebuilt.
What set me off is a more recent example where the bunker is right of the green, sloping away, with a creek and native to the right. The bunker was shapped with very slight cupping and very little build up of the low side lip. I didn't hit my ball there but it was obvious that being left with no shot was very possible. This bunker is being re built.
I've edited my initial post as it is obvious I over stated the issue, but I am curios if this is something you have seen?
Correct me if I'm wrong, but even in the UK they slope the sand so the ball doesn't run tight against the sod wall, right? And while you may have to play away from the hole, you can still play.