Vehicle levitation?

[159_Archer]

In an MP mission last night I 'drove' the lead tank of a small column over a rail-bridge and mayhem ensued in the following vehicles.

 

Some collided and got stuck, whilst 2 climbed the girders of the rail-bridge and stopped to admire the view (I assume!).

 

I tried to drive the girder-climbers down, but just ended-up crashing off the bridge and landing upside-down, Thinking these vehicles lost, I left them and then untangled a mess as seen below on the bridge ramp; this resulted in another vehicle on its side.

 

I left them and carried on with the remaining vehicles, only to notice shortly after that all the vehicles scattered around the bridges had 'righted' themselves! Is this a new Russian secret-weapon?!

 

Or was it instigated to correct the first error in a fashion...:D