Thanks Q interesting and informative link it shows that the full "System" as it should be deployed requires three specialist, dedicated vehicles:

1: Buk Missile System Complete

2: Command & Control Vehicle

This is the vehicle fitted with communications and medium range air defence radar. It is this radar that would find and identify any potential target and then pass it on to the:

3: Missile Launch Vehicle

The large smooth dome seen on the right of the vehicle's "turret" houses the missile's fire control radar (Initial "gathering beam" and target acquisition radar) and the "camera-like" piece of kit mounted above, and just behind it possibly provides early flight guidance until the missile's own sensors lock onto target. The fire control radar has no means of interrogating a target but in local control, i.e. in use without the Command & Control Vehicle, the fire control radar will lock onto a target if pointed in the direction of an aircraft. This capability is built into the system so that launchers can afford some degree of protection should Command vehicles get knocked out (Priorities in attacking any armoured formation from the air is to take out the air defence component first then take out the armour - In attacking the air defence component the priority is to identify and take out the command vehicles first then the launchers themselves)

As Akenaton says the video is inconclusive and could only show a Launcher Vehicle repositioning.

The most damning "evidence" to date is the recorded voice traffic between a "Separatist" Commander, Igor Bezler, and a Russian Intelligence Officer, Colonel Vasily Geranin of the GRU in which the former reports the shooting down of a Ukrainian aircraft at around the same time Flight MH17 was shot down.