Jay, The analysis was partially inconclusive. The analysis was limited to the grip's mechanical characteristics as I do not have access as yet to any electrical schematics.
MANUFACTURER'S WARNINGS: (1) The grip is not waterproof. (2) Never disassemble the grip yourself. This will void the warranty. (3) Remove the batteries when not used for an extended period. (4) Do not carry or store the grip with batteries installed together with other metal objects. Do not short-circuit the battery grip with batteries installed. (Editorial note: these seem to all be very generally applicable warnings).
GRIP DISASSMBLY WHEN ATTACHED TO THE CAMERA: The only dis-assembly fasteners that I could find on the grip are on the top side (so they will be covered and concealed when attached to the camera (I suspect this is the basic design of all D800 grips - can't speak for all the Nikon models' grips). There are also no fasteners that I could find inside the batter compartment (that would be accessible with the grip attached). Those factors indicate that there is no fault protection from a damage to the attachment mechanism that would render it unremovable. (Caveat: there may be fasteners under the the rubber surfaces on the grip, but I didn't want to disturb their attachment to find those fasteners.)
ATTACHMENT RELIABILITY: The other issue is how likely the grip could fail while attached to the camera. The attachment method is the classic design as far as I can tell with the thumb-wheel geared down to turn the tripod screw which is the only attachment of the grip to the camera. Without dis-assembling the grip, I can see that the tripod screw is brass and the thumb-wheel is plastic. The gear train connecting the thumb-wheel to the tripod screw is concealed, but I assume that it is a plastic to brass interface, the plastic being the more lightly loaded element (and thereby reducing the risk of failure). There seems to be considerable play between the two exposed elements, but I can't be sure because I didn't open the grip. There may be other parts inside that complicate the failure risk, but in my opinion because this is a bargain grip, I don't that they spared any expense that the customer did not need and could not see.
FINALLY, A SINGLE POINT FAILURE ASSESSMENT (AND PSEUDDO-TUTORIAL): In the space industry we rely heavily on redundancy for reliable and long-life operation, and the complexity in the application of remote redundancy there is significantly more complex than what we have on the D800 grip. One factor related to redundancy is the redundant unit's ability to be deactivated (remotely removed from service). If a redundant unit fails so that it cannot be turned off, as long as it has no other failure that prevents the system from operating, it is not a single point failure (this is also referred to as "single fault tolerance"). Analogous to this condition for the grip is as follows: (condition 1) If the grip fails such that it cannot be removed, as long as the camera can still function, the battery replaced when necessary, etc., the failure is not a single point failure and not considered critical. (Condition 2) if the grip fails such that the camera cannot operate but removal of the grip allows recovery of the camera operation, that too is not a single point failure. Therefore the grip does not represent a critical or single point failure (mechanically).
CONCLUSION: So, from this assessment, I will conclude that in my opinion the risk of failure is minimal (although no quantitative assessment is available), and perhaps more importantly multiple failures (rendering the grip unremovable and rendering the camera inoperative) do not appear to be related (and you won't find yourself with an inoperable camera in the field because of the grip alone).
Another Editorial Note: This analysis/assessment was way overkill for two reasons. (1) I suspect that almost all of the aftermarket grips (and even the Nikon brand grip) would be evaluated the same, and (2) it took me longer to write this text than it did to examine the grip itself! I hope you enjoyed reading it.