Good vid, but not so much an oops. Quite a common occurrence at a Military airshow. The T-birds make it part of their act, as do the Angels. The "Vapor cone" can occur at speeds lower than the sound barrier and are not a visual display of an aircraft breaking the sound barrier...It's whats known as
Prandtl-Glauert singularity, which has to to with air pressure response slightly below, or above the speed of sound. (Transonic)
Always a sight to behold, for sure....