It's a good video, but as I posted in the comments there, the dud rate was a lot higher than the stated 2%.
As documented in the Oil Division Final Report and its Appendix from the U.S. Strategic Bombing Survey., an analysis of raids against three major German oil-chemical plants found that, out of a total of 146,004 USAAF and RAF bombs dropped, 18,834 of them (12.9%) fell within the plant area. Of those 18,834 bombs landing within the plant area, 2,677 of them (14.2%) failed to explode. That's an overall dud rate of 1 in 7.
An examination of USAAF raids against 13 oil and chemical plants found that out of 16,620 bombs which landed in the target area 2,004 did not explode, a dud rate of 12.1%. RAF raids against the same targets had 6,154 bombs falling within the target area of which 1,168 failed to detonate, a dud rate of 19.0%. That's nearly 1 in 8 American and 1 in 5 British bombs failing to explode.
In some cases the fuzes failing to initiate is why the bomb didn't explode; in a few instances the arming safety wire was still attached which prevented the fuze from operating. In most cases, however, bombs failed to detonate because they landed flat as a result of the tail fins partially or completely separating from the bomb during its descent. If the bomb lands flat then neither the nose nor tail fuze is triggered and thus no detonation.