What might normally take several days to determine was announced while the devices were still laying amid smoking debris.
They weren't claiming to know the status of the internals. Elsewhere Farsi speakers have said the quote was regarding the external appearance of the recorders.
They state the recorders have an internal memory, and "they" (recorders, not memory module) are showing physical damage.
Seem wires got crossed and not realised the subject "they" changed in the course of those few sentences...