Another view of the collision here:
Video: US Fighter planes collide during Duxford air display - Telegraph
Breaking from vic is always going to require a specific brief - details of which are not in the public domain. But I'm not sure that anyone would
ever attempt to break 'blind' without knowing
precisely where the aicraft ahead is, H Peacock.
But the AAIB will no doubt investigate the briefing and activity during the break very comprehensively. Fortunately there were no deaths, so it shouldn't take long for the cause of the collision to be established.
Other forums have indicated concern at some of the organisational aspects of this event - something which won't go unnoticed by the AAIB if indeed it is relevant.