Regardless of the never-ending debate around exactly at what point are you considered "committed" into the restriction (by the time the car driver would have seen the van, reacted and braked to a halt, they'd probably have been in the restriction), the van driver was an aggressive ****. They delayed themselves far more by asserting their perceived "priority", forcing the confrontation and faffing around that ensued, than they would if they'd just allowed the car to complete its traversal of the restriction.
