Ouch, must have been a bummer of a debrief.
The first take-off almost looks like he was making a mil-power take-off instead of using AB. Apparently he unloaded the squat switches enough to allow the gear to retract. Great ejection seat.
Another "bad day" story involving Mig-29: https://www.defenseworld.net/news/29137/Ukrainian_MiG_29_Damaged_After_Drunk_Officer_Rams_Car_into_Jet#.YFIMgdzdiUk
Looking at it again, it almost looks like he forgot to pull the throttles back or hit the fire pushbuttons. Pretty fast sled with 40,000 lbst or so.
In airliner cockpit videos, you hear one pilot say "positive rate (of climb)" and the other will say "gear up". These guys should make sure they have the positive rate before they pull the gear handle!