The aircraft in the vid is definately a MiG-29. I spent many years in the Royal Observer Corps doing aircraft recognition to a very high standard. The MiG-29 has completed some tight turns to get into position. Its leading edge slats will be deployed and from that camera angle the wing tip is not clearly visible.
The missile that you see will be coming from the inboard wing pylon nearest the tip. The deployment of the slats at that distance will make it appear as if the missile has come off the wing-tip. The aircraft is not a Flanker of any variant and definately not a MiG-25.
Cheers
TJ