I have to disagree with this comment... Those tyres do not look to be lowered, and reducing the tyre pressure is the cardinal rule of driving in sand. Lowering tyre pressure will help in mud and rock also.
Should have been more clear. Yes they should have already lowered their tyre pressure before driving in the sand as always. What I meant lowering the pressure in the already buried vehicles wouldn't have made a difference due to the way they were stuck.
What they needed were a bunch of long handled shovels