what i see. bear in mind i ain't been up in around 5 years.
approach looked sloppy. looked like they were off center on short final, and centered as they got to the threshold. looked way late in flaring. i'm presuming that his left hand is on the throttle? although i don't know what civilian aircraft has left hand throttle. i make that presumption only because i see his hand press in when the right seat guy presses the throttle in. anyway.....if that was the throttle, i didn't see him pull to idle when he flared, then i see the right seat guy press it open.
when the throttle's opened, i see the plane bank hard left,(1st bad link in the chain) and judging by the sight picture, looks like only aileron correction. i feel there needed to be rudder correction there too. next, i see the right seat guy pull the throttle back, while they're still in a climb.(2nd bad link in the chain) i think this set up the stall that ultimately took them into the trees. right after he pulls throttle, and they both look around, he firewalls it again. at this point, it looks like the plane just started dropping the nose to the left. left seat guy looked to be doing just aileron/elevator correction, which accelerated the stall.(3rd bad link)
all that said, if right seat guy was an instructor, he should've been on the stick and pedals right back off the runway(as soon as the plane initially banked left). if he wasn't an instructor, then he shouldn't have touched that throttle at all.
of course this is all conjecture. i could be wrong. it happened a couple times i think.