The truck was coming from the direction the camera was pointing, and the gate on that ("near") side of the track was mounted on that signal/gate pylon on the right. (You can actually see the gate being test-operated in the video...)
The train was traveling from right to left from that viewpoint -- and it came to a stop with the rear unit right at the crossing/point of collision.
The truck cab/chassis was knocked backward and almost across the width of the road's pavement (not very far...).
IF the gate was, indeed, down before the truck moved onto the track, the truck would have had to go around the gate arm on its "free" left end -- and, then turn (right) in the direction of the train to go (left) around the end of the gate on the opposite side of the track.
In order to go around the far end of the other gate, the truck would have had to drive "up" the track (in the direction of the oncoming train for at least the length of the crossing arms (full left-right width of the crossing).
That would have placed the two vehicles in a near-head-on collision position -- with damage all across the front of the train engine.
BUT -- the collision damage on the train engine was on the left front corner, and the collision point on the truck was its right front corner.
Now comes the "fun part": '-)
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Notice that, in the video, the gate on the truck's approach side of the crossing was not only functional, post collision -- the wooden gate arm was still whole and unbroken! Still post-collision photos show both gate arms down -- and intact.
IF that gate was down during the collision -- why wasn't it smashed to splinters as the truck came flying back through it?
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Look closely -- right along the top of the ambulance on the far side -- and along the road centerline: that wooden gate arm is down -- and undamaged!
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Per Occam's Razor, the simplest, most likely answer is: That "near" gate was in the "UP" position when the collision occurred!
Also, facebook comments by "locals" claimed that that the gate(s) at that crossing had been operating "erratically" for some time...
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More to come...