I have never had the need or inclination to dismantle my Mk.3 bolt which has "The Rivet" mod. It would have been nice to understand exactly what the rivet does or prevents from happening which he didn't touch on.
A further point is that a lot of the problems encountered with bolt jamming in the trenches was attributed to the bolt stop distorting the same lug that fractured in the test when the bolt was repeatedly opened sharply. As a result, a larger bolt stop was fitted to many rifles which may be why the the bolt in the test was retained in the receiver rather than blowing out completely.
I still wouldn't want my face in the way though!