I know what the Egyptians said, but wondered if they had the capability?
I believe that either during or subsequent to the accident where the Egyptian authorities violently disagreed with the NTSB conclusions (the suicide vs flight controls failure one) that the Egyptians bought a FDR etc lab capability from FlightScape, now CAE-Flightscape, which is the software provider to a number of the "big" accident agencies (if you've seen a recent "official" FDR plot, chances are you've seen a Flightscape plot).
While having the kit doesn't always equate to having the expertise, I think it's safe to say they do have the ability to do what they say, unless, as has been mentioned, the units are so badly damaged only the original manufacturer can read them (which can be the case with the "big boys" as well)