Long time lurker, thought I'd post something as I know this stuff...
Flash memory chips have stored "static" charge in them in a pattern that sets what the data is. The charges only "leak" out if exposed to other strong electric charges, radiation or heat above about 160c. Data retention is actually very robust under most circumstances. They can also take silly levels of G because they are so lightweight.
The memory chips also have anti static diodes on each pin internally, significantly reducing their vulnerability to ESD, but people should still take care in case they have a "huge" amount if charge built up. Generally in most situations the ESD diodes can handle it no problem.
Moisture in plastic encapsulated chips is only a problem if they are heated suddenly (over a few seconds), where the moisture absorbed in the plastic can turn to steam, "popcorning" the chip case. Not a problem here as the temps are being kept lowish, just to dry them out.
Scraping off the conformal (or resin encapsulation) coating isn't a problem with a screwdriver, as the circuit boards used are generally of a very high quality, with thicker than usual "tracks". Even if the plastic case or pin is damaged, it is possible to erode away the plastic chip case to expose the silicon chip inside it. Then under a microscope, it is possible laser scan the flash memory to read out the data directly, depending in the reflected light polarisation per data bit.
In this way any flash memory can be read, from any device no matter how secure it is.
The youtube video of the people wearing winter gloves to handle the FDR was interesting, but nothing in there would have me concerned. I'd have done the exact same. No-one would ever plug in the FDR without carefully examining the circuit board very carefully first. You need to expose everything just like they did to check it. Only then after multiple expert examinations would i plug it into a reader- which also has many safeguards to avoid accidental damage to the data.
Hope this helps clear things up. Very curious to know what they find in this case. Unusual end of flight to say the least.