I have actually..
Page 316
Astral beings cannot push physical objects..
This is true. In the first two cases You have a physical object The van and the mage. who is tied to an astral object, A barrier and the mages astral form, that meet up with a purely astral form that isn't moving., In this case a ward.
This divide has always kinda been. If you're on the astral plane you can't activate triggers on the physical plane. So if a ghoul was to run through a purely astral barrier, he'd probally get astral intersected. Especially if he was forced through the bubble by something purely physical.
In the first two examples the physical object was the truck and the elevator. The astral barrier can't stop this.
However, Page 315, A barrier on the physical plane exists as a solid barrier to a bunch of magic stuff.
also on page 315, a mana barrier can be a physical entity, or astral. You choose which plane to cast it on.
Astral intersection isn't when two astral objects touch. Its when a third physical object forces one astral object into an other. Otherwise, ghouls explode when they touch eachother and Mana barrier becomes the mage killer.