Did we ever establish how the Russian Metrojet device was detonated, is it possible we have the same situation here,?
We even still - half a year after incident - don't have any positive conclusion from Egyptians led investigation, no officially presented case (or versions). Also Russian aviation and security authority still flying back and forth, checking "improvements" in Egypt airport security... (On the other hands, why bothers if they not officially agreed that it was terrorist act?).