G-LOC ?
...that referenced Flight URL doesn't have it right.
CNN broadcast another (better quality) amateur video this week.
Again, Blue Angel #6 was performing an aggressive, high-G, left descending turn for the low altitude rejoin. As #6 passes co-altitude (~500 ft AGL) behind the straight & level leader, he has 80-90 degrees of left bank and about 10 degrees nose low pitch. His nose is still 30-40 degrees right of the leader's heading -- and obviously is going to over-shoot the rejoin.
The #6 aircraft seems to be under control ... no apparent stall or smoke/flames, etc. Looks like a relatively smooth, continuous descent into the treetops... however, with no attempt to re-postion (barrel roll ?) or compensate for the over-shoot.
As DD mentioned here, G-LOC seems probable.
The U.S Navy reportedly will issue preliminary findings in 3 weeks (... that's real quick for a government investigation).