Crab,
You make my point for me.
The test by Sikorky allowed an extra delay in isolating the system....then carried on and was called off after the max fuel endurance was reached. They were testing their engineered system for certification and it worked fine. But we all know the rest of the story which enforces my position that if we say "Run Dry" it should mean "DRY".
Even those other "Trapped" fluid designs sound good but just as in the 92...the question has to be asked about even rare to the point of being an act of God kind of failure shifts you into being in a "DRY" situation.
If the drain plug were to remove itself by mystical reasons....would that cause a loss of lubricant? Sounds far fetched but then who would have guessed the 92 thing would happen? Lots of experts AFTER the fact knew of course but it made it into Service before it presented itself.