They heard 3 loud pops right before the plane dipped to the right...Probably an engine stall, just like that Vid of a Mig-29. U can actually here some loud cracking sounds in the vid posted on the first page, right before he looses it.
I always like to look on the bright side. We know Russian seats can save a pilots butt doing this kinda stuff, and now we know our American seats Can also
Great reaction time by the pilot. I probably would have been toast.