If you're a safety pilot, that close to another airplane and you're not actually watching it, I'm curious as to what they were doing?
Probably trying to work out what V2 was doing! It looks like passing underneath V1 was not briefed so trying to second guess what came next would have been very difficult in real time. It would seem that it was very lucky for the crew of V1 that they were not casualties 3 and 4