Recent clip of Dr. Garry Nolan getting asked about why UFOs keep crashing. His answer:
1) The UFO tech is advanced but still unstable, can perhaps even be brought down purposefully by humans via EM pulse (mentioned by other researchers as well) or natural causes that produce EM such as lightning strikes
2) There is "evidence" that all NHI do not comport to the same command structure, could be many things in tension with each other like 1600s colonial powers fighting or "unhappy with each other", for raw materials on Planet Earth. Is this what was seen in the skies over
Nuremberg in 1561? I don't think Cs have indicated that there is a tension between these forces because there is a clear hierarchy based on physical and mental abilities (Humanoid Orions >> Minturians ~> Reptilians > Grays).
The video has some other interesting bits as well. Doesn't provide any actual evidence though.