Equivalent level of safety findings are made when literal compliance with a certification regulation cannot be shown and compensating factors exist which can be shown to provide an equivalent level of safety.
Crab,
The MRGB does meet the literal interpretation of the FAR, because 29.927 has two options within it - either demonstrate that failure is "extremely remote," or demonstrate 30 minutes running following oil loss. In this case, SAC demonstrated to the FAA/EASA that "failure was extremely remote," so no ELOS was required. Sitting in our armchairs a few years later, that might be a debatable topic, but essentially you are answering your own questions without realising it.