Nobody is going to be talking about an unstart over the radio in an emergency situation. It took 2-3 seconds between the unstart and the aircraft disintegrating.
Unstart is a lot less evocative than “flameout” as used in the Top Gun movie. Flameout sounds like the plane is on fire. Especially if garbled.
Meanwhile, if your righter pilot sounds like he said engine start while flying? That’s only gonna happen if the engine already shut down. So that’s only ambiguous until the pilot keeps talking, in which case you know he was able to restart the engine before losing consciousness, versus the end of that conversation.