It’s pretty hard to ignore that Mishna, actually. It is obviously spoken by those who have seen it. They lived there. And, the Mishna is not being theoretical. This doesn’t stop anyone from giving alternate Pshatim in the Pasuk and it’s fine. The Ralbag is not really taking on Chazal head on. He wants to give a Pshat that satisfies him.
Old Man and Ari-Free’s approach maat very well be how out took place. I wrote that on the coffee room someplace but can’t find it now. I suggested that her turning around allowed enough time for the sulfur and salt to catch up with her and consume her. When salt consumes something you get one big pile of salt.
This would mean that not only was she punished, but she was punished by her own actions. We find this concept often how a person gets rewarded by their actions.