That doesn't mean that the cylinder wasn't walking or ovalizing and didn't contribute to the ring or piston failure.
But detonation is the primary killer of RS-T's on stock compression. If you are looking for a margin of safety do 2 things:
1.get good engine management.
2. Make sure you intercool it well.
Beyond that, you don't need to spend a ton of money on expensive rods, etc. But dropping the CR with a good set of pistons or an Ej257 bottom end would be a good cost effective way to approach it...