Why did they exceed the Barber pole/red line by 120-150 knots if they were taught that exceeding such limits could cause aircraft structural failure or loss of control? How would exceeding Red line by such a wide margin be constructive to completing their mission?
Firstly they were not bothered about using the same aircraft again, and secondly if there had been an attempt to intercept them - then they only needed a "missile on a trajectory".