Hi there, I'm no expert and I will probably get shot down ( excuse the poor pun) but your very nice model appeared to be tail heavy to me with a rearward Cof G. the dropping of the tail and the resulting high incidence of the wing causes the air flow over the top of the wing to break up with total loss of lift and it falls out of the sky. Just my two pence worth ( for what it's worth) Hope you get it flying well again.
Okay, I will pitch in (pun intended). I thought you flew it very well if it was tail heavy. But when it pitched up (intentional or not) it seemed to lose a lot of lift and then quickly stalled. I agree with the others posting here, that moving your plane's center of gravity closer to the front of your model should have it flying nicer. I would try moving your battery forward if possible. She looks really good, so don't give up on her!
wheres your trim set?
CG is at? most of the time the main wing spar is a good place to start, Normally 25-30% back from the leading edge of the main wing. The flight went well considering she was tail heavy,.................experiance speaking.
If you go back and review from 1:12 you will see what happened. You rolled left(before pole) and after the pole you were inverted and what you did was pull up elevator which caused the ground gods to accept your plane.
What is weird was your launch and forward flight wasn't bad(maybe a touch of - CG) but it flew okay. The turns were weird. I think you had too much elevator which led to your demise.